It's complicated because MTBs have become stupid and switched to through axles, and to make things more complicated (stupid) there are a couple different sized through axles as I understand it. This is a pretty good article to explain it, although it goes into a bunch of bogus "benefits" of the rear through axle: http://www.pinkbike.com/news/12x142-explained.html

The Chain Reaction site has poor descriptions for the sizing. After each size it should either say "QR" or "through axle."

OP: your bike has a standard 135 x 10mm QR rear axle. So that's the one you want. You definitely do NOT want the 135/142 x 12mm (12 is the hollow axle diameter) through axle version. The other complication is what front axle your fork is made for. Interestingly Chain Reaction does not seem to offer a QR front wheel along with the QR rear wheel. They only offer the QR rear wheel with a 15mm through axle front. Which I find very strange.