First off I am new here. I am looking at getting a new mountain bike, my last one was a huffy superia bought in 1996. Currently I am debating between a mongoose ledge 2.1 for 129.99 at wal-mart, the cheap option, a specialized rockhopper 669.99 at the local bike shop, or a trek marlin 7 also 669.99 at the local bike shop. I am a bigger guy about 6'1" and 325 lbs, 42/44 waist and 32" inseam, I plan on riding mostly back roads and a few area bike trails, maybe occasionally a harder trail if I go on vacation. I also looked at diamondback, genesis, and nishiki. The genesis is a 29 and cheap but the the others are more then the trek. I also looked at a trek marlin 6 for 579.99. I am leaning towards the trek primarily because it has hyd disc brakes, 29" tires, lifetime warranty, and I have heard trek is the only ones without a weight limit on their bikes, a plus for me. Any help would be appreciated, thank you.