John,
Why not go with some T5 fittings?.
I'm not aware off-hand of anny minimum hieghts, but I do know there are minimum lux levels for most types of work.
Using a T5 system, you can have the fittings a lot higher off the floor.
You also (if used in an industrial situation) have no problems with strobo-scopic effect.
You also have a lower wattage per fitting and therefore, less heat loss, as there is no wire-wound ballast to power as there is only a High Frequency Ballast, no starters to wear out and the tubes last longer.
The best part about these fittings is the fact that they give a higher output (lumens/watt) than any other light source currently on the market.
The T5 tube was designed with a new Tri-phosphor mix in the tubes.(No Mercury either)
These are slowly taking on Metal-Halide lamps for a preferred light source in a lot of applications.
They are so light-wieght (as opposed to the bulk of the M-H control gear) and virtually maintenance-free, it would be a crime to specify anything less.
This is just my own opinion.
