Depends a bit on what you want.
If you are looking for a vacation home or townhome for a week, Windsor Hills is by far the most popular spot mentioned here on the DISBoards. Read a few posts for more details. There are a couple of ways to access these units; they are privately owned, but there are a couple of management companies that handle the lion's share of rentals.
If you want something with a bit more of a resort feel, then there are tons of timeshare rentals available in the area. All will have 2 bedroom units that sleep up to 8 people, albeit you lose some of the convenience when you cram that many in (2 people at least sleeping in the living room on a pull-out). Several resorts also offer 3 bedroom units that would fit a crowd of 7 very comfortably. Popular timeshare resorts close to the park are the two Sherton Vistanas (Resort and Villages), Hilton Grand Vacation Club I-Drive, Orange Lake Country Club (Holiday Inn), or Silver Lake. And of course Bonnet Creek is right on the Disney property. We own at Sheraton Vistana Resort and at Silver Lake and both are great places to stay near Disney, but Vistana has far more amenities.
All of these resorts can be booked through your favorite web travel site, or direct from the hotel chain.
And if you really like Disney, consider "renting" DVC points from an owner and staying at one of the larger resort suites. This is probably cheaper than multiple hotel rooms, but costs more than a good deal off site. Again, there's lots of information on this board to get you started.
When staying offsite, you should also consider the cost of a rental car if not driving and daily parking at the parks ($13, pay once per day only). With 7 to transport, you'll need a pretty expensive rental! Also take into account that you can cook some of your own meals as the options above all have full kitchens - that can save a bundle over restaurants, especially with 7 mouths to feed.
Good Luck
