I just bought my first road bike on ebay, which I know is not ideal in terms of fit, but i'm pressed for cash and I also wanted something that was cheap enough to replace if it gets stolen once I head back to school.

I ended up purchasing a specialized tricross comp, but the previous owner had switched the crank from the original FSA gossamer double with 38/48 chainrings to a Rocky Mountain (a brand I am not familiar with regarding quality) triple with 28/38/48 chainrings. The previous owner then did not change the front derailleur, so the bike is only capable of shifting the 28/38.

Regardless of the quality of the current crank, I plan on switching it to a double crankset similar to the original, but i'm not sure what I should do chainring wise. I live in a very flat area, and would consider myself a relatively strong rider. I'm looking to buy FSA, since I worked in their North American warehouse for a summer (picked up the cycling bug there...), but should I get close to the original cyclocross oriented 38/48 or go with a more road oriented 39/53 since I plan on using the bike for road riding? I also have no idea what to do in terms of the crank arm length. The frame is 60cm, and I have long legs, should I try and go for 175mm or will 172.5mm be long enough?

As a side note, would anyone know what that used Rocky Mountain crank might be worth?