If a 1500kg commodore with single pot brakes can get out there on a race track, you should have no problems stopping with 4 pot calipers with a car of an R32's weight.
I took my 19 year old R31 sedan onto the track last year..which has got over 300,000km on the clock and just pretty much a normal daily driver.. and cained the living beejeebus out of it for 20 laps or so (not straight true), and nothing broke, so you should be right
Don't stress too much.. and figure "if it breaks, it was going to break anyhow". Soon as you think that, it's all just fun