Brakes-
When I first bought the car in 6/05, there was no ABS system and a proportioning valve was used:
I hated not having ABS because the brakes would always lock up on the autocross as this video from Oct 29, 2005 shows:
Right click and "save target as"
In June 2006, we installed a complete ABS system (ABS pump, ABS computer in trunk, all 4 wheel sensors) and removed the prop valve. The line-loc is still hooked up and functional even without pulling the ABS fuse. One item that improved "brake feel" was the check-valve that you can see in pic below in the gray hose coming off the booster.
Brakes Pads:
I think the Hawk HPS is a great autocross pad. The Hawk HP+ is slightly better but dusts a lot more.
The stock system works great for autocross.
On the road course, I think they work great too. I don't have ducting. But also I don't "kill" the brakes because I take it a little easy and brake early.
Stainless steel brake lines:
Porterfield R4-S brake pads AP331 $ 79.95 AP332 $ 69.95 - I used these when I first got the car but they didn't impress me. Hawks now.