Thanks guys.
Heres the layout I am building from...where would vacuum be available here for the stock booster? My brakes are rebuilt SC units on stock rotors but I have no problems, they are predictable and never fade so I would like to keep them as-is. In a hot cabin I would prefer to keep the boosting there as it would be quite a workout on top of everything else going on. The car is very light so the brakes seem matched fine.
Oh and David, I drive more like Hans Schmuck. I was thinking of the activities at the end of the main straight...from WOT to a bit of trailbraking through the left, on the throttle again then down hard on the brakes. That's a lot of variation in the boost levels which I would think would in turn make the brake booster see varying vacuum signal, which would in turn make the brakes feel unpredictible?