For the one or two plants you'll put in there, 3 of those bulbs is probably plenty. Of course more light means faster growth, but the big concern is during budding. With more light, even CFL, you'll have to be more concerned with temperature. Don't underestimate the importance of exchanging air. For best results don't let the temp of the leaves get above 80, and this means temps at the canopy should not be above 82. Transpiration can slow or stop above that. For lighting, proper colors are important as well. 5500-6500K for veg, 2400-3200K for bud. Preferably 5700 and 2500.