Let us in on your budget for the hotel (max $ per night you can spend), and we can give you some better insight.
Right off the bat, if you FOR SURE want a larger room/suite with a separate area so the kids can go to bed and you can stay up, here are the best options:
-All Star Family suite (cheapest option...$250/night). If you're considering staying offsite to save $$$, I'd highly recommend this instead, as staying onsite should be your top priority for a first trip.
-Wilderness Lodge Deluxe Room (Junior Suite)-this would be my personal choice. In fact, that is where we plan to stay in 2009 when we go with our boys (almost 5yo & 3yo). This room is approx $585/night in value season, but INCLUDES concierge service, which is a steal for all you get. This room has a standard room w/2 queen beds and a separate living area separated from the bedroom by french doors. The living area has a sofa that converts to a queen bed, an extra television, access to the shared balcony (the other access is from the bedroom), and a "wet bar" area that has a sink, coffee maker, and refrigerator. The closet (armoire) is HUGE, and the bathroom can be accessed from either the bedroom or living area. Look into this option...the Wilderness Lodge is an exceptional resort for a family's first trip, and these junior suites provide QUITE a bang for your buck.
-DVC villas, as mentioned, although note that a 1 bedroom villa only has ONE bed (king) in the master bedroom. The other sleeping area is a pull out queen sofa bed in the living room. You would have to put your kids to sleep on the sofa bed and then retreat to your bedroom if you wanted to stay up, but then you'd not really have access to the kitchen area, laundry, etc. You'd really need a 2 br villa for what you want to do, and those are $$$$$, around $800/night.