Which shimano derailleur for my carerra subway 1???

habahaba Posts: 12
edited June 2011 in MTB beginners
Hi guys
Im totally new to this. First time building a bike from scratch ( frame only ) and Im stuck at derailleurs, dont know nothing about. Im confused with sizes, which I can fit to my bike? I need front and rear, I allready have shimano revo shifters. Please help me with this one. I spend few hrs searching, browsing, but no success:\ I can provide u with pics if u want to. Please help me, I can't wait to take it on the road:]]]]