H.
Trailers are so much safer than kid seats on bikes. Also, you will be able to use the trailer much longer than you would a bike seat as we all know how fast those little ones grow. I have a Burley D'lite for my soon to be three year old and a one year old. They love having their own little space to travel in.
I would encourage you to get the best trailer you can within your budget. A great place to look for a used one is Craig's list..there are usually 2-child Burleys for around $200 or $250 and less for one-child trailers or for other brands of 2-child ones.
As for bikes, I'd say go to a couple of different bike shops and talk to the folks there. They are pretty knowledgeable about matching bikes to your particular needs and will be able to get you and your husband the proper fit. Then at least you will have a good idea of what to look for if you decide to buy a bike elsewhere.
Hope this helps..and have fun biking!!