Love that F100! (I've got a '71 F250 4x4).
I'm new to prerunner stuff and clearly this is not your first rodeo but what size tire are you going to run? You mention moving the spare inside. I can tell you a Bronco gets real small when you introduce a 37" tire to the interior. Had one laying flat on the floor when mine was a '3 seater' and that was about all she wrote for storage.
I've since replaced the 3rd seat with a PRP bench with reasonable foot space. Now there's no room inside for a spare but there is for other stuff. I'd be curious to see a stout tire carrier bumper design that wouldn't try to break away after a couple of your jumps.
As for glass, I've got Fiberwerx of uncertain age. Held up pretty good so far. Broke a lower mount on a front fender but that's really due to the amateur install.