I have twins in the family, me not blessed w/double birth but 6 single ones. I could not recommend more the Baby jogger city stroller, double. It is light weight, fold pretty flat, seats lay down, alot of seats don't go down far enough to "rest". Steers super easy w/one hand, pushes so nice! The only thing I do not know is the ability for 2 car seats. I do know you can do one. It is a side/side, but it fits in doors, my front door or the mall. In most isles and is not hard to manoeuvre! I have had more than my share of strollers and by far the BEST all the way around was this one!! The handle adjusts for short(me) or tall(hubby), even the kids like pushing it(they fight over it) mine are from 16m-3y apart. I use it on the mountain trails or the city mall. It cleans easliy just wipe it out, I have even hosed it out!
As for other things. Bundle Me...not sure where you live, but the Bundle Me lite, is good everywhere. You do not need other blankets that fall off and get dirty on the ground and you don't know it till the tire is tangled! There is the infant and toddler size, you might ask for two of each...and then there is the original (heavier) depends if you live where it is COLD!! Also easier to pull out and wash then taking apart the car seat, when there is an accident or they don't like their lunch and it comes up w/out warning.
Help...ask for it, see if someone is willing to come over for 2 hours a week for a month or so...you WILL need it. (be nice to get a couple different people for a couple different days) Even if it is just to be "normal" for a short time. .up to about 6months it is very exhausting(mentally, emotionally, physically,) then they start to be more fun and not so exhausting! This way you can even go out shopping w/someone and enjoy it!
sleep positioners, helps keep them on their side, and kinda hugs them, helps them "rest" a bit better. In my observations they tend to sleep better in the same crib..but again only observations I do not have them. Also the sleepers that wrap them, mine only worked for the first month or so...but it was a big difference, they wrap them tight, comes w/velcro tabs to keep them, I used extra large flannel receiving blankets, home made, 3ft x 3ft....great for EVERYTHING...and they do not out grow it...they thin out after 100's of washings, but they all still love them and they are so soft.
Some kind of wrap or carrier, then you can still get some things done (not that you should be doing it, but you will want to) and carry one, hopefully the other is sleeping:) Keep in mind if it bothers you to carry a backpack or something on your neck. I had to carry my back pack w/1 strap, 2 tend to put too much weight on my neck if not positioned right and makes me nauseous...same thing w/some carriers. Also, read on them, as not all good for short people! I returned some because of that(have NO waist). I believe the Moby or similar is good for all sizes, and grows w/baby. Don't need additional pieces for small vs large.
Mattress protector if you don't already have one, for the crib.I have used the ones for "potty training" they go on top and come off w/out sheets etc getting wet..and wash easy!! and they are good once out of the crib in a bed! or your bed waiting for the big day...water break! ;)
I used porta crib for naps(two story) and when outside to keep them off the ground but safe and can see the world still. also when traveling for their bed. Use to it at home so no change when in a strange place it was their 2nd bed! and folds up to NOTHING, so it is easy to put away when company comes over, and travels well.
When you decide on doing things a certain way, be open to change...the babies may not go with you on your decision and want it different...but it is OKAY! Congratulations on your NEW ARRIVALS to be!! get lots of rest now!