The internal structure was pretty easy to build. I used a piece of 5/8 inch wood and traced the shape of the bow-front onto it and then used a jigsaw to cut it out. I did this twice, so I could get an upper curved piece and a lower curved piece, then added straight-bits of wood to match the lip of the tank. Added vertical braces and you have pick #1 (basically)
The doors were a PITA... In the end, i ended up tracing the curve shape onto a 2x4 and using a scroll-saw to cut the curves... doing this twice created and upper and lower curved support for the "planks" to get screwed into. Using one screw only, in the center, allowed the boards to more naturally follow the curve, but if I was to do it again, I would run each edge of the board(planks) thru the table saw to miter the edges for a tighter fit.
I used black silicone caulking to seal the gaps, and weather stripping at the moveable seams. The entire structure was painted with a white platic based paint.. it's super easy to wipe down from salt creep/splashing, etc..
The Luminbright is set so the bulb is 17" above the tank. This was determined based upon reading online. I did not use a PAR meter to determine the "best" spot for the light...
The T5's are mounted on 45degree "planks" and the reflectors are angled to provide downward coverage and shoot the blue actinics into the tank... In my design they are too low... by about 1/2 inch... I need to move them up just a bit...
Everything is open, to allow for as much air flow as possible, no fans are used, however I will add some as i think the bulb life is shortened due to the heat... I do not have heat issues in the water because of the basement sump and the basement is much cooler than the rest of the house... but some active fan-cooling would likely increase bulb life and from what I've read increase bulb performance for the T5's...
Hope that helps...
It was the biggest most complicated woodworking project i've done... i'm happy with the result... Though I really look forward to a rectangular tank cabinet build this falll...

Curves suck!!!!