i know the sp1/sp2/cbr600rr callipers bolt straight onto the rvf

what about those of a 2000 firestorm?

Firestorm calipers are the same as RVF400 (some are gold though), so yes they will fit.

yep just flogged my firestorm with gold calipers and they are indeed RVF calipers.
just to note i have SP1 calipers on mine now, and a blade master cyl, and using original spongy hoses, the lever feels quite spongy (i like that feel so in the event of a panic brake you dont tuck the front so easily) but it sure stops well enough even if it feels a bit soggy.

thanx for the replies