Cool , I?d love to give it a go .
Half cage is grand for what you?re doing and the power of the car , should stiffen things up nicely, would an x bar across the 2 wheel well pick up points be of any addition? Or even just a harness bar?
Its a bit decieving in the pick i posted as the rear legs are the shorter ones going to the rear strut towers front hoop is bolted at the floor and again through the top brackets into the original b pillar seat belt mount points so this should help keep things square and the harness bar runs parallel across the rear
I have 32mm and 25mm tubing i plan to make rear bracing and front tower brace