Sounds like a closet in a Victorian house, lol.
If you can find a T5 fixture that is narrow enough to fit that space, that's a DEFINITE option. You can get special bulbs for veg and for flower, and swap them out for the appropriate life cycle. Hint, in early flower (week 1 and 2 of flower), you can use half-and-half blue/red to control stretch better than red spectrum alone.
I don't like CFLs for a space that size just because of the hassle and even heat of it all.
You can also start out cheap and stuff 3 4' shop lights with 2 x 40w t12 bulbs in there for veg and then flower under 3 small HPS lamps, if you really want to spend some cash on cooling.