I'm assuming you mean T5 fluorescent?
I would not specifically buy anything fluorescent, metal hallide, etc. You have to change lamps regularly because their radiation output fades and quality lamps are expensive.
Go with LED. Tons of options out there for a 36" LED aquarium strip light.
If you have the T5 fixtures on hand, by all means use them, especially if they're older, better made stuff. Problem is like said, today's replacement fluorescent tubes suck compared to the ones made years ago.