SW - still considering that option so may PM you (thought you were on holiday though
). I'd kind of like to be able to do it myself, but not sure whether trying to do the whole thing at once is the best place to start! (My localest LBS is selling 105 for more than I'd pay for 6800 online which put me off using a shop slightly...)
Fairly sure I've worked out all the bits I need - current front mech is braze on but with a 34.9mm converter thing according to the internet. Just need to decide if I'm brave enough!