RE: free standing stand to shoot from
Welcome to the forums...................the only thing I can think of would be a tripod stand and they are expensive (250-500 bucks), Do you have any other tree besides the one they are roosting in that you could shoot from? For a non-hunter such as I assume you are,A 15 foot ladder stand would probably work well, (can be had as cheaply as $80), if you can find a tree that would be away from the tree they are in by say,20-30 yards and you have a good tele lens on your camera, you should do fine.