im in a dilema right now, found a really great deal on a set of matching FSA k Force carbon Seat post and stem, only dilema is the stem is a 90mm and the color way of the stem has the red lines while my supersix is the team color blue/green black white... dude is asking $100 for the set should i bite? my bike is a size 52,im not sure but i read somewhere the stock stem is either 100mm or 90mm .. would this be a wise purchase for me?