ISIS BB's are not -- I repeat not crap. They will probably outlast a exterior BB ( much better sealed and protected from the elements). The ISIS is relagated to 2nd/3rd level BB status because of its limited use with current cranks (yes some curent cranks still use the ISIS BB). I do not know about the cost of Shimano components in Northern Europe -- maybe Sram is cheaper. I use Sram , Campagnolo and Shimano -- down tube , bar end and duel purpose shifters. They all work very nice. I do prefer the more positive feel of the Sram & Campagnolo shifters over the new Shimano shifters but the new Shimano STI levers perform their duties very nice. I do agree that the GXP BB is not as good as any of the other major brands. So a Sram group with another brand of BB/crank may work better. I have 2 of my bikes with Sram Force working with FSA SLK Light cranks w/Shimano BB's. One crank is a compact and the other is a standard crank. It will be no problem for a mechanic to make a complete Sram group work very well with your Cannondale but I would think twice about the GXP BB.