Hey MCS I used to work as a mechanic in Olympic Cycles in Nottingham during my Uni days and agree with you totally, find your local bike shop, get to know them and the use them for all you need, they will do a deal to, plus they will help with set-up etc. it does remind me I should try a duathlon sometime!
Good luck Oscarr, you will do it, the training is done, the will is there...you are ready, the most important thing is to enjoy it