For game use, I like Blade-Tech. I use a stright drop belt holster and their double moonclip carriers. The Blade-Tech two moonclip carrier works better for me than the metal single clip alternatives.
Of course, another option for carryiing moonclips for competition is just to hang them off a "cartridge loop" western-style gun-belt...
Stright drop, where the gun is straight up and down in relation to the belt, is most common in competition holsters in my experience. An FBI-cant means the butt is raked slightly forward and muzzle is, therefore, pointing slightly to the shooter's rear (as opposed to straight down). Some prefer it for a speed draw, so the gun can be drawn in a forward motion and opposed to straight up. I don't find it faster for me -- but its a matter of personal preference.
Forward cant is more useful, IMHO, in a concealed carry holster because it can help hide the butt of the gun a bit better.