Personally I think it would look awesome having stainless steel cables suspending your lights from 14' ceilings! Right now your tank kind of acts like a room divider, so why not extend that upwards if you know what I mean ?
I don't think I've ever seen a rectangular fixture suspended with only one cable. What would stop it from spinning?
Your best bet might be to visit a couple lighting stores (not big box stores), but an actual lighting store. Maybe you can even find a fixture you could retrofit as your light rack?
Also keep in mind where your ballasts will go, along with cabling. Also, I HIGHLY recommend using a laser-line plumb-bob for properly aligning your cables to the ceiling!