My 15 y/o son is looking for 26er, hardtail, geared, front suspension, disc brakes. He's about 125# and is pretty skilled and rides aggressively on some pretty technical single track we have nearby. Just out-grew his old steed. We're looking at the obvious ones, Trek, C-Dale, Gary Fisher. What bikes are a good value for the above described in the $1,000 range? Thanks.