I would still get a quality light. Stomatopod is correct about the fish's preference but your fish will show better color under a quality light rather than regular fluorescent lights. There are different t-5 bulb combinations that you can play around with and most of the LED fixtures can be dimmed and adjusted as well. Also, with better lighting, potentially and along with other factors, can grow better algae whereas poor lighting (or even t-5 that are past their recommended life span) will grow some slime algae (cyanobacteria) like crazy. While the LEDs can be quite expensive but save in the long term because of the lack of bulb replacement.
With a fish only aquarium, it would be a highly advised to invest in a very good skimmer to help out with the feedings of that many fish.
Good Luck
Mike