The DVC resorts, as autumngirl has laid out with those spectacular room diagrams, offers some stunning accommodation. If renting direct from Disney these are relatively expensive, but do offer wonderful accommodations. A cheaper option is to rent points from a DVC member, that route would probably save you between $100-250 a night depending on the resort you choose and the days of the week ( Friday and Saturday nights have a high points cost)
With the ages of your kids (i.e. one under the age of 3) you could rent a one bedroom DVC unit that would mean the older kids would have to sleep sharing the pull out double sofa bed ( something my girls were ok doing into their teens) that is in the living room, you would still have a separate bedroom from the kids and it would probably save you between $75-200 a night depending on resort and time of year.
Another (cheaper) option , again as long as the kids are OK sharing a pull down double bed, would be one of the Cabins at fort Wilderness. These have a double bed and bunk beds in the bedroom, a separate kitchen/dining/living area with pull down "murphy" double bed. The cabins aren't quite up to the high standard of the DVC units, but the do offer good sized accommodation at a reasonable price.
The one bedroom unit or the cabins aren't exactly what you've asked for, but they would be considerably cheaper than renting a 2 bedroom DVC unit from Disney. I'll try to rank the costs of your options (roughly) starting from cheapest.
1) a one bedroom DVC unit at OKW renting points from an owner ($200-300 a night) . To avoid me having to type the same message on each option that are renting points this comment is good for any time you'd rent points from an owner. Try to avoid weekends these can really jack up the average price of the stay.
2) A cabin at Fort Wilderness (from Disney) $220-275 a night
3) a one bedroom DVC (other than OKW resort) renting points from an owner ($250-350 a night) .
4) a 2 bedroom at OKW renting points from an owner ($275-400 a night)
5) a 2 bedroom DVC unit (other than OKW) renting points from an owner ($325-450 a night)
6) a one bedroom unit from Disney ($350-500 a night)
7) a 2 bedroom unit from Disney ($450+)
Which resort is the better choice depends very much on the individual, the Beachclub has a fantastic pool area, by far the best of Disney's hotels, but it's likely to be the most expensive. How much time you'd spend using the pool may or may not justify the extra cost. It ( and Boardwalk) also offer better locations in terms of speed into some of the parks. Epcot is a short walk, MGM a short boat ride. All of BCV, Wilderness Lodge and BW have a much more "hotel" feel about them, that may be something thats a plus for you or not, OKW feels much more like a small village/condo development and would be quite a lot cheaper if you were to go the point rental route.