Just for navigation, it would probably be way cheaper, at least in terms of labor,
to put a mount on the A-pillar for a Garmin or TomTom unit for that in-your-
face location.
The radio bezel is not screwed down, and it's really carrying no weight. Any
head unit mounted to it is likely to rattle the bezel loose from the push tab
slots in the center stack (especially if driven off road), assuming it doesn't
break from the weight first.
It might be possible to build a metal HU mount that screws to the actual
radio or heat/ac control location. This could include a new mount for the
control, too. It could also be built in pieces or a smaller piece, rather than
one huge piece.
The heat/ac vent hoses could be a separate bezel, below the radio and heat/ac
control, for instance. Or the hoses could vent in the middle with the control
at the bottom in the original radio location. Then, yeah, some fiberglass
fabrication might be necessary, but the whole deal would be a lot stronger
than trying to rely on the bezel alone.
My problem (at least one of them) is I like the vents up high at the stock
location. I'm not sure putting them in the middle would work as well.
I don't have a picture for it yet, so I'll keep head-tripping it; I'd like a 10"
unit high enough to really see.