It will be fine for both vegetative and flowering. When you have more space though, a HPS light is MUCH better for flower.
Remember that using flourescents, you need to keep your plants short and flat by training them so that all the parts of the plant are very close to the lights. 1-3 inches is a good distance; if you have a lot of lights, they can be a bit further away.
T12s or T8s are the size bulb. T8 is brighter but T12 is cooler. The inexpensive fixtures at home depot that I show in the picture will accept either size.