Hi guys, my name is mike and i am trying to get into mountain biking as a new means of exercise. I have lost 70lbs over the last year and am looking for a new and awesome way to work out. i live in Charlotte NC and am looking at getting my first bike. My budget is $600. I have narrowed it down to two bikes and i am looking for some suggestions and advice..choice #1 is a slightly used 2008 Haro Shift V3 with disc brakes and full suspension for $500 and my second option is a 2010 Trek 4300 with disc brakes and front suspension for $560.....which one would you guys choose or should i look at something else? thanks!