I have a line on a Trek Marlin 2012 to buy. Needs new wheels, cassette, chain & shock. They are all a bit Rusty. Already has upgraded Avid 7 brakes. Good deal at $300? What shock would you recommend? I am a heavier rider at 250lb and 6'2" (long body/short legs). Mostly, city (lots of Potholes & curb jumping), cross country and some single track, but no aggressive downhill stuff. Obviously, want something good, but not super expensive. Also, a good STURDY but not too heavy wheel suggestion would be helpful. Note: plan on doing most of the upgrade work myself.