Apparently this is a definitive list of all R-spec tyres available in Australia, for what it's worth.

Avon (sorry don't know the model name)
Bridgestone Potenza RE55S
Dunlop Direzza DZ03G
Falken Avensis RT615
Federal 595 RS-R
Hankook Ventus Z211
Hoosier Sports Cars DOT Radial Wet/A6 & R6
Kumho Ecsta V70A
Michelin Pilot Sport Cup
Pirelli P Zero Corsa
Silverstone FTZ Sport Type RR
Toyo Proxes R888
Yokohama ADVAN AO48R

Thanks to Tarmac magazine, the 1st issue of which I picked up last week.  It's a good read.  www.tarmac-mag.com