My advice would be to use epoxy only. Epoxy is a much better adhesive and stronger structurally. Use the good stuff and buy the pumps with the resin - makes it much easier to mix. Also I would use cloth and not mat.
Make it easier for yourself and completely cut away the forward pillars to the roofline and refab them, then you will be able to spread the load under the roof and behind the body. As one other poster mentioned you can not bend 'glass like metal and it will be very difficult if not impossible to modify them esp. changing the angle of the pillars.