T.S.
We'll be heading to Orlando this summer as well. We have a timeshare and traded to stay at Marriott's Harbor Lake, which I think someone already mentioned (and is probably what the first poster meant by Pirates Cove). It has a splash park, Pirate ship, water slides, etc. We chose it primarily for the pools even through there are other timeshares closer to Disney.
Also, since it's timeshares (but you can book like a hotel through Marriott), you could probably book the week for within your price range and still get at least a full 1-bedroom, with kitchen etc. which will give you more space to spread out when you finally come in from the pools.