I don't recommend VHO. While it's a good light, I can assure you that you'll be pi$$ing money into the toilet with them compared to a T5HO sytem.
I know T5's cost more, but VERY shortly you'll feel the sting of having to replace the VHO tubes every 6 months, and also the problem of not having many VHO tubes to choose from.
VHO's use a LOT more wattage than a similar-size T5, yet they don't produce the kind of growth that a T5 can. Lots of wattage = costly electric bills.
There are a LOT of T5 tubes to choose from, you can get a year out of them before you replace them, and they put out a lot more usable light, watt for watt, versus VHO.