I am trying to build my own bike for the first time. I admit, I don't know a lot about parts. I recently purchased a TREK 1500 SLR (2007) frame w/fork. I have other parts on another bike I want to use if possible. I bought a Shimano Tiagra Road Crankset (FC-4500) 52/39 and have a Shimano Tiagra HG-50 (9 speed) on a 700c wheelset. I want to use all of this on the TREK and need confirmation if I can use them, plus what would be the best, moderate priced derailleur and brake set for this bike.