glassworks makes some of the best fiberglass in the offroad racing industry. they supply to most of the big race teams (riviera, pfluger, herbst, etc). i used to have the glassworks fenders on my XJ and they fit up great, now i have the hannemann units (which rusty's sells) and they are a decent fender.
the glassworks fenders are high quality and pretty damn thick, the rustys/hannemann are thin and flimsy.
IMO, the glassworks fenders are the best bet for your $$$