FL has a few funny rules, but for CCS in general...
Almost all classes allow unlimited singles in unlimited frames. The only classes it would NOT be legal for are:
Supersport classes (LW, MW, HW, UL) (requires stock street-legal frame, stock wheels, etc)
GP Singles (125 2-stroke GP bikes only)
Supertwins
It would be most competetive in ultra-lightweight superbike. Other classes to consider would be LW Superbike, LW GP, GTL and Thunderbike.
-z.