Where are you located? The Hap Baker range in Westminster is outdoors with a covered shooting area, think of a shed without the "downrange" wall. They have benches for standing use on the pistol range but they also have a couple of stools there if you want to sit. I've also seen a pistol bench rest hanging on the back wall, I'm sure one of the RSOs would show you how to use it if you ask.
Remember you need to be a member of a club to join AGC.