I highly recommend Wilson Combat's.
Just as good are the Kimber Pro-Tac Mags, which will fit flush in most standard Government frame 1911's. They also include two base pads you can mount with included screws if needed, but they function fine either way.
VIGILIA PRETIUM LIBERTATIS
"The price of liberty is vigilance"
America is at an awkward stage. It's too late to work within the system, but too early to shoot the bastards.