Hi Sherry! If you are wishing to keep the group together in one place then the Tree House Villas are a good bet as they will sleep nine. The other villas will sleep eight and yes there will be someone out in the living area on the pull out couches. They are large rooms though and sometimes guests don't mind the sleeper sofa. All other resort Villa two bedroom accommodations will sleep only eight.
There is one alternative but it is costly. It is the three bedroom Grand Villa at Saratoga Springs, Animal Kingdom Jambo and Kidani House, Bay Lake Towers, Boardwalk, and Old Key West resorts. All three bedrooms have either queen or king beds and all three are attached with a bathroom. There is most often a living area pull out sofa if needed but each villa has a little difference. You cannot book this on line and would need to call for this reservation. This villa will sleep a total of 12 guests when all beds are used to maximum. Please click
HERE to see this link for Saratoga Springs example.
There are many homes for rent outside of Disney property but I never recommend them as you then lose all the great privileges of being a Disney resort guest. It also takes a lot of time to come and go from parks and with a group this large you will have some wishing to be on different time schedules.
A final option is to book more then one room. Most resorts will have connecting rooms for two but then the third and fourth would not internally connect. You could book a villa and a studio if you wanted kitchen facilities. And don't forget to consider the number of bathrooms..it is important!
Let me know if any of these options work...and if there is anything else we can do for you in your planning stages of your Disney vacation!