You can use a cfl as a ccfl I have done so a few times, in other words you dont
have to use the tubes heaters, not sure whether its brightness is affected or not, you will still be able to make a decent light from it.
The heaters aid ionization of the gas within the tube, if your circuit design produces high voltage spikes that'll do the same job.
In a cfl theres a cap across the heater connections, this is tuned to the switching freq of the lamps inverter, not very practical with a simple oscillator like you'll be building.
For a couple of people I have put togther a fuji disposeable camera circuit that powers a cfl, they are quite good, if you can get your hands on an old scanner, one with a tube not leds they usually have a 12v to fluorescent tube driver that can be used to drive a cfl, or ccfl.
Leds are more efficient than fluorescents, the latter can be softer light, for reading and working leds are great.