I don't know if I'm missing something, or what, but it seemed to me the obvious solution would be an adjustable gas tube and something like the YHM flip up sight.
Rednecks... Keeping the woods critter-free since March 2, 1836. (TX Independence Day)
I'm going to use the words "clip" and "Long Colt" every chance I get. It grinds my gears to see new members attacked when we all know dang good and well what's being refered to.