I've never seen a glue on 'glass fender. Are you thinking of flares?
From a friend's experience with 'glass fenders on his Ranger you need to make sure the stuff lines up and is the same dimensions from each peice to the next. He got a set of Perry's Fiber front 'glass for his Ranger and they were horrible. Stuff doesn't line up at all, mounting points were just wrong and off, and from side to side they fit very different. He got it to work but wasn't happy at all.
Also remember you'll have to find a good way to ship these. If UPS can f-up a Detroit Locker or a bumper they can F-up a fiberglass fender.

As for the rear, the only good way is pop-rivets, dzus (sp?) fasteners, or bolts. That's what I've seen on Broncos, BII's, K5's, Explorers, etc setup for desert stuff. Autofab's Bronco rears go on that way. You cut out the fenderwell according to their specifications, drill some holes, and mount up their fenders. There's no way to make it look pretty without doing major body work that would fall off the first time you offroaded it.