Our family went to the AAU Nationals in 2000. We rented a 4 bedroom home that had two master bedrooms. By sharing it with another family we saved a lot of money. You might be surprised how competitive the price is to rent a house there instead of a hotel or condo. Also, pay special attention to LOCATION. The subdivision we stayed in was 4 miles southwest of the ballfields and it was a perfect spot at that time. Families from our team were spread out all over Orlando/Kissimmee and we heard many complaints about location (too far away) and neighborhood (not very nice/safe).
The company we rented from was:
www.loyaltyusa.com. Their rates are listed on each home's page so you can quickly see if the price is right for your family. There are a lot of pictures, too.