I agree with SadieKate and have swapped out almost everything on my old Surly except the headset and I let the LBS do that. But I also like to tinker and learn how things work. If you don't I wouldn't recommend trying to do it yourself. That said, you can also have the LBS build up a bike for you and I thought that was what allabouteve meant. I did this with my Orbea, which I love by the way. I have Shimano on my Orbea and I picked everything from gearing, handlebar, seatpost, pedals etc. My suggestion is to try Campy vs Shimano on a bike before you decide. I didn't like the way you had to shift on the Campy but all of this is just personal experience so try a few things before you have them build the bike up and they should be willing so swap out stems etc to get the bike to fit you properly which is probably the most important thing of all...