+1!

I'd suggest removing the rubber and if possible adjustable sways. A more grippy tire like Michelin Super Sports or Potenza RE-11 will help as well.

Then I'd suggest a rear cage, harness and buckets.

 

I looked at seats because there is no way to use my sport adaptive seats with a harness, you need a cutout or a bar.
What is your street tire wear like when set up with negative castor?
You can order everything custom on a new Porsche but the tires. Pirelli was my last choice. It's ok as they won't last long and then it will be super sports.

 

You mean caster ?

Caster doesn't wear tires faster. Toe and Camber does.
On the 997.2 chassi you don't need tons of negative camber to make the car work.

 

Yeah I screwed that up.. Do we have a consensus on tire wear with neg camber and toe in.

 

I got even tire wear from my set up. I don't drive at the street that much, but no problems so far.