When you say 8
bulbs, I don't know if that's 8 light fixtures with one bulb each, or 4 twin bulb fixtures (two bulbs each). Also you mention 540 watts, as well as 800 watts. 540 divided by 8 comes out to about 68 watts each. That seems like a lot of wattage for one 4 foot bulb. The T8's light's I plan to get are 32 watts per bulb (64 total watts for a twin light fixture), but I never checked the wattage of the T5's and I guess it's possible their twice the wattage of the T8's.
But any witch way I simply cant say if 540-800 total wattage of florescent light is enough for your planed setup. It not just the wattage, it's how evenly you can distribute the light around the plants. As well as not allowing the light source (bulbs/fixtures) to be to far away from the plants foliage (hopefully no more than 18 inches away). The more light sources you use, the more evenly you can distribute the light around the plant/s. But the florescent
lights still should be close to the plants foliage or the useful lumens will drop significantly, thus not do the plant much good (wasting your wattage/lumens). So your light array/configuration is extremely important to how well the florescent lighting will do for you.
To compound the issue of florescent lighting, you plan to grow three types of large bushy plants that continuously produce fruit. Even if you only planed to grow one of each, they get large and bushy (unless you trim the heck out of them). That makes it more difficult to evenly distribute the light to all the foliage. Even if the plant has a lot of nice looking leaves, only the leaves that are getting sufficient lighting will be able to do photosynthesis. It's just like having a lot of solar panels on the roof, the ones in the shade wont be doing much good. You would want to put them all in a place they get enough light or they wont be doing much good.
Usually I would say if you will be using 800 watts of electricity anyway, you would be better off using 2-400 watt, or 4-200 watt (for better light distribution) HID lights. But I can certainly understand if you are getting the lights for practically free. I wouldn't pass that up either (no mater what). Heck, with that many florescent lights, you'd be able to grow enough lettuce for everybody on your block.