your best hope is the marathon. forget the 13:00 5k, it ain't gonna happen. look at the american guys who have run under 13:10 ... it's obvious who had/has the potential to do that by the time they are 18, and you aren't it. you're the same age as German, and he *might* get to 13:00 5k, and he's already way, way better than you.
so like i said, the marathon is your best bet, and having said that, i'll tell you that you should skip the college running system and go straight into marathon training. lots and lots of miles, with a long-term goal of the 2016 or even 2020 olympic trials. like you said, you have 10 years, don't waste 4 or 5 of it running dinky XC meets in a D2 wasteland, or hoping you can walk on at some D1 pitstop where you'll be an afterthought.
i believe you can do it, but if you really want to be a professional, make the sacrifices, put in the miles now, do the training now. don't listen to the losers who say you'll get hurt (look at all the guys that get hurt in college anyway), or that you're too young (lots and lots of successful people in other endeavors skipped college because they knew exactly what they wanted to do and didn't want to waste time).
so what are you waiting for?