Personally....wouldnt worry about the rotors,unless u want a certain look or are going on the circuit. Lines are everything.U squeeze the lever=the line expands. Not as much pressure gets on them squezzers(the calipers). Get good lines .You can get stainless steel,or teflon coated. I've used SBS pads and a couple others for years . There's probably some Busa specific ones out there that one of the boys/girlz can quote ya . Like the man say's....."It's not the fall that killz ya,It's the sudden stop". Me....I like a sudden stop.Then ya dont end up part of that mini-van that just turned left in front of ya . If ya hit it....this is all thats left...
Braided hoses and EBC "HH" Sintered pads. On the road, on a stock bike (or even a mildly improved version
) they are probably the best braking upgrade you can get
If you go silly on the HP (in which case dosh is probably not really a consideration), then you could consider the complete race performance brake sets from "AP Racing" or "Brembo"; which include hoses, calipers pads....etc (the whole set ok). they are about £1200.00
I've seen some quad disc brake systems which looks the biz and must be pretty effective too considering the superbikes use them. Not sure about the price though.