reverb mount

Having not had a reverb before. Currently using giants own on my trance. I'm considering ordering one. Slightly confused about the trigger mount. I'd prefer it under the bar on the left. Currently have sram shifters and avid brakes on a matchmaker, so do I need a left mmx or right mmx. If I can't get it under the bar on the left using the mmx, i'd rather it above on the left. As long as I'm not stuck with it on the right.

Ok confusing babble over