I'm with the metal roof. They come with insulation pre-attached so should be OK for heat.
I've always thought I would add a separate second skin to keep out the the heat.
Like the old Landrover safari roof
No one on TD is gay. If suspect, it was probably because of the way they were reared.
I apologize if any offence was caused. unless it was intended.
You people, you think I know feck nothing; I tell you: I know feck all