I believe the biggest obstacle right now is the inverter, or ballast, which is damn expensive because CCFL starts up at some ridiculous voltage like 3000 volts or something, then goes down to maybe 300 or so while on.

I'm pretty sure you can grow plants with them, I just don't know how cost effective it would be. Maybe like LEDs, the initial expense is made up by the other savings in the long run. You just need the proper red and blue wavelengths or spectrums, and enough lumens. Like I said before, there are companies that will make whatever wavelength you want. I imagine this aint cheap.