^^Good idea there.
A 4-foot T5 fixture is pretty sweet for a long skinny closet. Get the BLUE bulbs for it, and keep 4-6 moms in 3 gallon pots, trained to a nice flat shallow canopy.
The New Waves are the fixtures I've had experience with, and I have been just DELIGHTED with them. A cheap near-substitute would be a set of shop lights fitted with T8 tubes of the 'daylight' or 'cool white' sort.
Don't forget to plan your ventilation AND circulation; in an oddly shaped space, it is often the limiting factor!