I plan on using a combination of products / methods to reduce the heat on my build. First is the Lizard Skin thermal spray insulation and sound insulation - each applied at least 2x normal coats... maybe 3x if it's reasonable on the cost. This will be done not only on the floor and firewall but also the interior of the hard top.
The windows will be tinted with a UV-blocking clear film. Specifically blocks the heat but allows the visible light through. The down-side is that it also blocks the GPS signal so the solution will be to mount the GPS up high and let the signal go through the fiberglass top. Will be testing the performance of the GPS up high like that before actually getting the window tint done.
The hard top will be painted body colour rather than the typical flat black.
The hard top will get a head liner on the interior with a layer of insulation.
All done it should be very well insulated. I'm looking forward to seeing how it turns out.