Thanks for all the advice everybody! I've been doing HPDE for a few years, but this was my first in the Boxster. I didn't make that clear. However, I'm definitely hearing that it might be worth it to stay stock for a season anyway. I like that plan.
I do have the 17 wheels, with 225 front 255 rears, and am loving the R-S3's so far. I also have put in the Brey-Krause roll bar...forgot to mention, but think that'll help with the safety part.
After reading everybody's advice, maybe I'll go with seats and harness first. As Steved0x mentioned. My wrists, forearms, and shoulders are killing me. I'm a small guy anyway, so I really have to put the death grip on the wheel to hold myself in place. And maybe I'll do that brake cooling mod, too.
I am near NCCAR and do plan on running there this season. I'm going to CMP in a few weeks and will prob run there a lot...and VIR (my fav) -also hoping to get to Summit point and Road Atlanta.
What tire pressures are you running? I started stock 29 psi front and 36 psi rear, and then added a few psi to the front to stay above the wear arrows on the tires. I think hot I was 35 front and 42 rear.
Here I am on my maiden voyage