Kansa and Shasta both have lameness issues.
If you are going to buy a horse that has soundness or soreness issues you have to be prepared to spend lots of $$, vet care isn't cheap. My moms horse coliced a few years ago and had to have surgury that was $8,000. Also, with some (or most) horse adoption agencys you do not own the horse for the first year or so. There is lots of restrictions about what you can and can't do with the horse. If they find out that the you aren't following the contract there will be some major fines.

What is it you are looking to do with a horse? What discipline? What is your budget? Do you prefer a mare or gelding? What age? What height? What training level? Is breed important to you? Where are you located? What are you going to do with the horse in the winter? Can you afford vet care, farrier, board, lessons, show fees, blankets, tack etc...?
If you anwser those questions I can look around for you.