Braze-ons can be had from several sources on the web. I've modified several bikes that way, just doing it on an old Motobecane. I generally add cable stops for shifters and brakes, downtube shifter bosses, water bottle bosses, sometimes I move brake bridge and add canti brake bosses, pump boss, front derrauleur mount boss and rack boss barrel. Some I silver braze, some brass braze. The cleaning and painting afterward is lot harder that the brazing part, but it's worth it to me. The source I usually use is: http://store.airbomb.com/ba/asp/cc.105/ab/items.htm.