Which Post Mount Brackets Do I Need?

iLukeKendall Posts: 160
edited December 2013 in MTB buying advice
I'm about to pull the trigger on a set of Shimano XT Hydraulic disc brakes, after giving up on the Hayes Dyno Sport ones that came with my bike (literally no stopping power whatsoever after several adjustments).

I'm thinking of upping my rotors to 180mm at the same time, and wondered how to tell which mounting bracket I need? The bike came with 160mm rotors, so I'm assuming the existing brackets wouldn't offset the calliper enough?
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