The key to finding a good villa is extensive searching on the internet.
I would recommend Indian Point and Cumbrian Lakes, both just off the 192 in Kissimmee and near restaurants, supermarkets etc and within easy reach of the I4 - 20 mins approx. to Disney/Universal.
Decide on what preferences you have, normally we have found the 4 bedroom villas are nicer.
Try and find one where the pool is private and not overlooked by other properties, a fence surround is ideal.
A South Facing pool means you get the sun all day.
Make sure the villa is reasonably new as the homes get so much stick from the weather they require a lot of looking after to keep them in prime condition.
The first time we booked one was a disaster and we ended up re-locating to another at Chatham Park after a week.
The villa was located in the Davenport area and 10 years old, we got there and was shocked to see the home was in need of severe re-furbishment, the interior was a disgrace and the pool area was so bad we couldn't use it for 3 days - devastating for us because our little boy is Autistic but loves water.
The owner's web site was years out of date and the information misleading.
Hence our extensive searching and our being fussy over the age of the property, it MUST be less than 3/4 years old.
Realise most home owner's are great , we just picked bad one.
There is nothing wrong with being fussy, after all it's you who is paying the money, ask plenty of questions, there are only 3 of us and most owners will offer price reductions if you ask for one based on the size of your party.
villas2000.com and vr360homes.co.uk are good sites.