Hi Karl
I tried a twin T5HO that was way to bright, I had to raise it quite high and didnt like the light spill into the room though I did like the colours it produced in the tank over the LED I now have, 2 Aquaray mini 400 LED tiles on a controller each running at only 35%.
This is how it looks although the planting/layout has changed now.
http://www.ukaps.org/forum/threads/tmc-mini-400-led-tile.29829/
As before you could jump in with both feet and splash out on LED bars etc or maybe retrofit T5's into the Roma or go slowly and see what can be achieved with the T8's, others might be able to advise in the lighting section.