Since you're hosed on capacity anyway, look at doing some wheelies.
Smith 627 Performance Center .357 Magnum 8-shot and 358 Lightweight Hunter 7-shot .357 with a 6" barrel. The 627 (maybe the 358 too) are relieved for using moon clips. Time to start emulating Jerry Miculek.
And with 1911s already on your radar with these sub-standard capacity mags, you should investigate the .50 G.I. cartridge for some serious weight downrange. The .460 Rowland would be fun for you also…off the top of my head I want to say 230gr JHP cooking along at 1,200 fps or so (way wrong…I looked it up, 230gr SMOKING along at 1,340 fps and 930 ft.lbs. of energy!).
Back to wheelies, that .460 S&W Magnum that blue's kin had at Marana was an AWESOME set up! That muzzle brake made rapid fire pretty darn easy…just don't let anyone stand to the side of you (Tom did stand next to me…but he's TOM dude).
Does this mean that Desert Eagles are on your list now?