You will find that renting a condo/townhome/villa is a much better value than a suites based hotel room... as long as you can live without maid service and/or room service. The hard part is that there are so many choices., it can be daunting to pick one.
"Not too expensive" is very relative so if you want specific suggestions, you might want to post a price range. Just like hotels, you can find places from $70 ish to $250 ish per night, so just set a budget, then start searching for things in your price range. Most of the places in the Formosa Gardens area of Kissimmee, are about 5-8 min drive to AK, 10-12 min drive to MGM / Epcot and 15 min drive to the TTC parking lot for MK. If you don't mind driving 10-12 additional minutes to the parks then you can get homes out in the Davenport and Champions Gate for a very good rate.
There was a recent post regarding Seven Dwarfs Lane, which is in Kissimmee, and the OP got a rate of $500 (plus tax) for a week. This is a brand new development, but not as posh as Windsor Hills - and it is a little further away from the parks.
Here's some questions to consider when researching what you want. Do you want a full size pool, private splash pool and/or hot tub right at your home? Do you want the community pool to have a zero entry area or children's splash fountain area? How about a playground?
Once you've determined a budget and the amenities that you want, you'll be able to narrow down quite a bit.
Good luck!
Lisa
You will probably find a 3 bedroom will give you just that extra bit of space but still at a reasonable price 
