I'm on the verge of buying a RockShox Tora fork for my bike, and plan to use them with Hope Mono Mini M4 brakes. I'm stumped as to what mounting to buy for these, how do you guys find out this information?
What you need to know is the type of mounting you have on your fork and on your brakes to know what adaptor you need to get. There are IS (so-called international standard, used by Hope and Formula, among others), Post (used by Rockshox, Marzocchi for forks and Avid, Hayes for brakes, among others) and some manufacturer and/or fork specific mounts.
According to the link you provided, the fork has Post mounts. (From the description: Lower tubes: Magnesium, Post-disc mount). Hope uses IS mounts.
So you need a Front IS to Post adaptor.
The size of your disc is another important thing to know, since you might need a bigger adaptor for it.