replacing derailleur/shifter cables
 

On my mountain bike I have SRAM Attack grip shifters. I thought I read somewhere about SRAM shifters using 1.1mm cables vs 1.2mm. My question is, does that .1mm really matter or will I be fine using the 1.2mm cables. Also, where the heck can you find/order SRAM cables online? I googled it but all I can find are shifter care kits that come with a bunch of stuff that I don't need.

thanks for the help! :)