It is best to be there in person to do that. You might check out Gringo Tree (http://www.gringotree.com/cuenca/) and post your request there and see what kind of response you get, but I would not recommend renting anything sight unseen.
And thanks for suggestions Suzan! I did post on GringoTree and got a couple replies. I definitely won’t rent sight unseen! I may actually be able to do a trip there before we move so i can see places and make arrangements in advance.