You can veg with the hps... i did it for years, with no worries at all. Imo cfls are good for rooting clones and thats about it , they will give you very spindly and weak growth compared to hps or top end led.
How bigs the tent your using ?
Have you got intake and exhaust fans?
(Youll definitely need them for the hps)
And finally what medium and nutrients do you plan to use?