I would agree with AKV concierge, since there are only a handful of them. August is one of the easier months to book DVC and any of the other categories of rooms should be doable.
It also looks like SSR TreeHouse Villas are very hard to get, especially during the summer months. There are 30 THVs in the DVC inventory and I think families grab them up quickly because they cost the same as a 2 bedroom but they have three bedrooms. I just looked at the Resort Availability Thread for August 2010, which is just now coming into the 7-month window. It shows 22 dates unavailable, and 19 of them are for the THVs. Although that thread is not totally reliable, I think it shows how popular the THVs are with the Membership.