I am looking for a comfortable bike to ride around the socal desert. I am 6'3" and about 220 lbs. I think I need the power of a 400-450 to keep up with my friends. There is some sand riding, but much more riding over the bumpy stuff. Since I have a bad back, I want to have the best suspension for this kind of ride, with high reliability and not too much maintenance. Right now I'm looking at a '03 DRZ400E and a 03' WR450. Which of those two bikes do you think would be better suited for my needs, and why? Or is there another bike with Estart (required) that you suggest? Thanks for your opinions.