There's a total of one hotel on airport property - the Hyatt Regency that's located in the airport's terminal. All other "Airport" hotels are off property by at least a couple of miles but should have shuttles available if you need to get back to the airport the next day for transportation to Disney.
If you must absolutely have an on-airport property hotel then you'd be running a risk by going the Priceline or Hotwire route as there's always the possibility that you'll end up in another hotel that has the same star rating as the Hyatt.
So if it's the Hyatt Regency, period, then go out the Hyatt website for their price (look for specials there, too) then go to sites like hotels.com, expedia.com, travelocity.com, orbitz.com, priceline's fixed rate site, etc., to see if you can find a better price.
Dick Taylor