Long time lurker, first time poster. I am a complete neophyte to biking. That said, I think I have taken my entry level bike with Sora derailleurs/shifters about as far as I care to and would like to venture out on my first independent upgrade. Can someone tell me all of the parts I will need to buy to upgrade to a 105 grupo? I think I have the mechanics of the actual upgrade figured out, but I want to make sure that I am purchasing all of the necessary components.