As far as T-5 Vrs Halides I can tell you that it does make a difference on the top of the tank not so much on the bottom !!
I used a meter and measured Vho actinic's new T-5's New and old and various Halides.
The thing that surprised me was near the bottom of a tank say beyond 18" T-5's Lost less intensity and stayed more consistent even when they got old.
Now halides near the top portion are significantly brighter IF they are DE and say 10K.
I have 3 250 DE and 2 VHO on my 180 AGA. I may swap the vho over to t-5 some day but for now it's good, just takes more electricity.
You could go for a Wave 2k or a tunze wave box! If your buget allows it ?
:-)
Paul