J., I envy you. Singapore is TERRIFIC. What is important is that you have appropriate and decent housing provided - ON TOP OF SALARY. You do NOT want to live in a crackerjack box - your husband should be treated as an executive high enough in his station regarding housing. Don't accept a position without this.
You should have a Cost of Living Adjustment. Do NOT accept a local package. You need an expat package. You should have tax help as a perk, including tax equalization IF it is to your benefit (it might be better to just pay Singapore taxes if they cost you less. They should have a tax preparer working with you and tell you what is best for you.) It would be appropriate for them to allow you to join one of the many clubs - for instance, the Singapore American Club. Your husband should be talking to them about getting you a family membership. Considering the time you are talking about living there, the company would probably end up making money on the membership when they sell it after you repatriate.
Usually there is a clause that says that if you leave the posting within the first year, you have to pay back all the moving costs. However, you should ask them to add that if your husband DIES in the first year, that you are EXEMPTED from paying this back. They may "say" that this doesn't include death. That's nice. Tell them to put it in WRITING. Moving you over there can cost upwards of 6 figures and you don't want to have to be worrying about this, ever.
You need to take a look/see over there after the baby is born. Look at apartments/houses. I recommend a house over an apartment, quite honestly. If you find something you like, you can take measurements and know what furniture will fit and what stuff will fit. (That's what I did.) The closer in you are to the expensive part of the city (and the subway system), the more expensive and smaller the houses are. You need room for your family - don't let the company give you a small housing allowance. Your husband should have an idea of what decent housing costs are and know what the housing allowance is, and not accept this job unless they give you a big enough housing allowance.
If they are difficult with you about this, he should try to negotiate this with them because you are planning on homeschooling the kids, and they won't have to pay for an international school for them (which is quite expensive, by the way.) You could also use THAT as an "in" to getting a club membership. (He shouldn't bring that up first - only use that if he needs to!)
You may think that you don't need a club membership. You need to put that thought away, and I don't mean maybe. Meeting other Americans and other expats is PARAMOUNT to you acclimating to your new home overseas. You need to have friends. Your children need to have friends. It is hard to just meet the local people. I know what I'm talking about. Please believe me when I tell you this. Since you won't be a PTA mom and have your kids in the international schools, you NEED a club membership. This is where they will have pool access, a place to meet with other children, etc. They have a women's group that will help you figure out where to take the children for field trips and trips for you to enjoy as well.
Home visits are based, usually, on hardship. I would doubt that Singapore is high up on the "misery scale", like for instance, India. Singapore is probably one paid trip home a year. India, in comparison, is probably 4 trips out of the country per year. Perhaps the compensation package says that you can either have business tickets for each member of the family, OR you can get paid 75% of that in cash in order to buy your own ticket. That's what we did when living overseas, and we'd fly coach instead of business class so that we could use the rest of the money to go on vacations. You will want to get all the frequent flyer miles you can - that's really important so that you can start accruing them.
Before your husband accepts the job, you both need to read the compensation package. Will they sell your home? If they won't, you may need to consider renting it out. If you don't bring everything with you, will they store some of your belongings? If they don't, you'll have to figure out what to do with them.
You also need to know what the company will do for you in terms of a CAR. You will need to be able to drive. Your husband will need a car too. You cannot just assume that you'll take taxis. Taxis are hard to find during busy times of the day. I really mean that. Cars are VERY EXPENSIVE because you have to pay a freakingly HIGH fee in order to have one, on top of the cost of the car. The reason for this is that Singapore is a small island and the government doesn't want it to be totally overun with cars. So it costs a small fortune to have them. But you just CANNOT be expected to live life there without a car. The company should do this for you.
Moving like this can "free" you of too many belongings. It can be a gigantic pain in the rear, I know from experience. However, once you get through all your "stuff" and let go of the extras, life is easier. The company will tell you how many pounds and how much space in a sea container you can bring. I hope that it's a 40 foot container - that's a "normal" household (not large, but not tiny.) Perhaps this is something you can negotiate too, since they are talking about such a long assignment. You need to bring the stuff for your kids, like your books, baby stuff, etc. What you buy in the states is probably cheaper, to be honest. Take as much as you can with you. What I did was bring back every year in as many suitcases as I was allowed to carry, all the stuff that was too small for my kids (I gave it to a family back home who needed help) and the books and toys my younger one grew out of. That gave me plenty of room in my suitcases, coming back, with new clothes, etc. Make sure you take your photo albums, your silverware (it takes time to learn to eat with chopsticks) tampons, (their's are different and smaller), your DVD player (theirs won't play US based DVD's), US medicine, like over-the-counter stuff, and whatever the company will allow you to bring from your pantry.
I want you to know that I got my sea shipment in 6 weeks, J.. I do not think that you will have to worry about not getting your stuff in a timely manner. Asia handles this very well. You very well may have an air shipment, as well. We had 500 pounds in an air shipment and I put stuff in it that I needed right away.
Don't say "no" to hiring a domestic helper to come in and clean and cook for you, J.. It won't cost you all that much, and will make your life a lot easier. It's not easy living in a foreign country. Part of your job is to figure out HOW to live there. You can't do that if you are doing all the cleaning, cooking, teaching and rearing of your children. Accept help.
Your husband will most likely have a secretary who will be helping him. Accept her help, too. There will be lot's of things that need to be done. She can make a big difference for you.
IF you have the right kind of deal going into this (never, ever assume that they'll change the deal after you agree to go), you could put back some good money to help put your children though college, if you don't spend too much having great vacations. If you don't have a Cost of Living Allowance and housing allowance, you cannot afford to live there. The last thing you want to do is go live in a foreign country and be strapped. One of the reasons people do this is so that they can be fairly compensated for the hardship and difficulty of living in a place so foreign.
Good luck!
Dawn