I dont think you'll be able to fit 8 bulbs over a 55 with anything coming close to a decent reflector. T5 bulbs need indivisual relfectors for the to be really effective. I've got a 6 bulb TekT5 fixture over my 75, which is 6 inches wider than a 55 and I dont even know if I'd fit 8 over that. For a 55, I'd go with a 4 bulb fixture, again, with individual reflectors.