Those sound fine, I would just buy 1 more fixture for them. If you place a reflective surface in the area you are growing them it will help make the area brighter. (If you place aluminum foil on the sides and the bottom, or even use mirrors/buy mylar.) I would see how they do before you decide it isn't good enough. If they aren't working out you could invest in T5 fixtures. They are more efficient then T8 and last longer, though they produce a lot of heat and can be costly to buy in the beginning.