Was set to order them in from the UK until Fattima put me onto Just Brakes in Campbellfield (Vic). They sell RDA rotors for $50 EACH, less than half the cost of the DBA rotors from most other outlets.
RDA also do slotted and grooved sports rotors as well, again they seem to be about half the cost of DBA. Im sure they are available from other retailers ( i think i've seen them on eBay as well) but i got them here:
http://www.justbrakes.com.au/
usual disclaimers apply - no association with either company, i haven't tested them yet, no idea how long they will last or perform etc etc. just passing on some info that might save youse some $$$$$
