Hi, I'm new. I'm looking to get into the sport of mountain biking, and I need help with my bike choice. I'm looking at a Cannondale F7 Disc. Firstly, is that a good choice? Secondly, and more importantly, what size should I get? I'm 6' - 6' 1" and float around 175 pounds. Any input? BTW, another bike I have been eyeing is a Motobecane 400HT or 500HT...what are opinions on those? Any equivalents that anyone would suggest? Thanks!