Back when I was looking at them I found a series of videos by an ex-beemer mechanic on each of the maintenance parts of the R1200's and R1100's. It got into 90% of the stuff, like ignition, valves, clutches, rear drives, etc. IIRC there was a tool you could use to 'reset' the computer after service. I got the impression that you could do all the regular maintenance yourself.
The canbus is one of the tricky parts. Adding electrical accessories is a little touchy, but, could be done.
Or, you could be like my brother. Buy it new. Trade it in when the warranty runs out. Have all service done by BMW. :)