I am confused on what you are planning on doing with the lights. Do you mean to put them at the ceiling and light the entire room and grow plants at counter height? T12 fixtures work fine but they need to be close to the plants. Stronger, brighter lights can be placed further away but you can't take a low intensity bulb like the T12 and make up for further distance by simply adding more.
I would also add that if you are serious about growing successfully indoors under lights. The number one most important factor is the light! If your tight on cash then start small or cut back on other aspects of your budget but don't skimp on the lights.