Just a random thing to add as I couldn't find it on a quick search and have since found out the info.
The bolt that holds the brake pad carrier(impreza) on to the hub assembly is a m12x1.25. I'll wager as these cars get older there will be a lot more of the "I snapped this bolt....HELP!" posts.
This and it is usually cheaper to buy a loaded early wrx caliper w/bracket once you factor in the core, than it is just to buy the wrx pad carrier by itself, for those with an earlier impreza looking to upgrade to the early wrx brake setup.