Roll Cage design 87 1/2 coupe GT

[AV8oR]

Hi!

I am looking for a cage design for my Coupe. I have a friend who'll do the
bends and welds.
The only thing he needs is a design with the dimensions.

This is the first time I am doing something like this.
I have looked at bolt-ins/-ons from the usual sources and found them to be
waay overpriced for
the gain received.

What type/grade of metal and welding should be used for best results?
Anyone out there who has built one?

Any BTDTs would be great!!!
Thanks fellas!

Zafir 87 1/2 Coupe GT (se cuup wants too goo reecing)