Right here on the DIS, there are several DVC boards, including one for rentals. There's a sticky at the top of the rental board that you should read before trying to rent - it has a ton of great information.
While I didn't rent points for our stay (I got a pin with 20% off), my extended family and I shared a 2br at SSR. It was great. I think a 2 br would be a good solution for you as you'll have two bedrooms and one or two kids could sleep on the pull out couch in the living room, so you'll have three areas for sleeping vs. two. There's a kitchen with everything you'll need, a high chair and pack n play in the room, washer and dryer in the room, and 2 bathrooms. OKW has the biggest rooms for 2brs, I think all the rest are basically the same size. The treehouse villas weren't open yet when we were there, but I think each unit is accessable only by stairs -- a pain if you need to lug strollers. The 3 br villas fill up fast because DVC owners can book 11 months out.
Good luck researching and planning your trip!!