Andrea:
With two little ones and 6 adults, you need some privacy and extra bathrooms...I bet you'll also be spending a fair amount of time at the Magic Kingdom.
My recommendation: a 2-bedroom villa at either Wilderness Lodge or
Bay Lake Towers. You'll be a boat ride away from a nap for the kids (or the grandparents) at the lodge and a monorail ride or 10-minute walk to Bay Lake Towers. You'll find the accommodations well-suited with a bedroom housing two beds and one with a king. The living area for both villas provides plenty of floor space for a pack 'n' play or to use the sofa bed.
If cost is an issue, consider Old Key West. Although it seems like another Florida resort to some, for the price you can have boat-access to Downtown Disney for the adults. A villa or treehouse at Saratoga Springs can put you near the golf course if the men in the family enjoy that for relaxation.
Magic Kingdom tops the list for parks and if the kids will recognize Playhouse Disney characters and Pixar characters like Buzz Lightyear, Disney's Hollywood Studios would come in second--and don't miss the parades at either park. I always feel the vacation shouldn't be totally child-focused, so Epcot--even with small children--should be on your list. Attractions like Nemo and the interactive games in Innoventions make for suitable attractions. But it would still be fourth after Animal Kingdom where even young children can enjoy the shows, especially Flights of Wonder and the Lion King, Kilamanjaro Safari, and the Boneyard--a "dig" playground near Dinoland.
Feel free to come back if you've got more questions and need more help!
Whitney