This place was suggested, ( http://7aresort.com/index.php/lodges/ ) to me and may offer what you are thinking of? You could even work in some fishing on the Blanco. It's only about a half hour west of where we will be fishing on the San Marcos. I think they have some smaller cabins that would accommodate our group. I have not checked availability at this place. So far, I am the only one signed-up to go on this outing.
If we can get a few more commitements, I say we book a room or 2.