Have you considered an FZR600 as a track bike?
I have one for sale in MCN this week at £750! Complete with wets on spare rims and daylight MOT.
check out the details on
MCN website.
http://www.motorcyclenews.com/MCN/bikesforsale/searchresults/detail/?R=NXGN-7526997&mfy=0.000000