Unless things have changed you cannot have an extended baseplate on a WB magazine. The seated magazine fits flush to the bottom of the grip of the pistol. My s/s McCormick mags have 2 screw holes for plastic base pads but the holes don't matter. Doesn't matter either if they're blue or stainless. If you decide to try IPSC some day just screw some pads on them and rock and roll. The pads do make it easier to get a good seat for a fast reload.
The Shooting Star classic would probably be what you would want for a full sized 1911, either blue or s/s. I live in eastern NC where things rust, I love stainless. Compact 1911s are not WB legal.
Check out the prices on midway usa too.