If you're looking for 4 wheel drive, look at some crossover vehicles. I prefer the GMC Acadia and the Chevy Traverse because they are the only two in this class that seat 7, but have a 2+2+3 seating arrangement with captains chairs in the middle row. The makes it easy to access the back bench, just like in a mini van. I used to own a Ford Freestyle, which I LOVED, however I only had one child back then and it had a 2+3+2 seating arrangement and it would not be easy to use the back seat and 3 car seats would NOT fit across the middle bench. I did a lot of research and looked into some of the crossovers that had captains chairs. Most of them only seat 6, and many have a center console so you have to flip one of the captains chairs up to access the back (big issue if you have 2 in 5 point harness seats).
A GREAT option for your husband is the Mazda 5. Its called a mini minivan. It seats 6 in a 2+2+2 arrangement. The middle row is captains chairs and they slide forward and backward to accommodate adults and kids, or make it easier to buckle kids in, etc. My MAIN reason for not choosing this vehicle for me is that when all 6 seats are in use there is basically NO room in the trunk, so for the main family car its not practical. If the back two seats are not in use you can fold them down and have a TON of room. Since you have a van, this might be the perfect car for your hubby since he won't need to keep the kids in there all the time. Also the back is split, so if he needs to keep all the car seats in there, the one seat not being used can be folded down as trunk space. They are way better on gas then a SUV, van, or crossover.
My husband tells me that Ford is coming out with one of these soon as well, called the Focus C-Max, its also available electric and with a electric and tiny gas motor (like the chevy volt). We've given this type of vehicle lots of thought, and will probably get an electric one in the future as a commuter vehicle for me. But we'd have to have a larger crossover for when we travel (we love to camp, take bikes, etc...) as a third vehicle, as my husband will also get an electricfocus for commuting. :)
Hope this is helpful. Happy car shopping and congratulations on the next baby!