The 90 gal. was my 1st attempt (here in OR, had a 55 gal. in Hawaii). Hubby built the cabinet for it to sit on. Don't have pix & I tore it down to sell. Now he wants to put it up again. The boxes didn't look bad but should have been more narrow. It was always a pain to do anything in the tank without moving the lights & boxes. A hood works best when you can afford one, or in my case, when the hubby gets to the Honey Do list. (Any contractor's wife will tell you she's the last to get something done unless it's something that really excites him. An aggressive tank might do the trick.) I had originally thought he could use some kind of swing up hinge to connect to the lights & the tank.
As far as the over heating went, it all has to do with the location in my family room. Windows, sliding glass door & skylights, lack of air circulation in that corner, & wood stove in the next room (in winter time) were all contributing factors to the temp problem. Even had to turn the heater in the tank way down to the 60's & then back up when it got colder. Had to build shade cloth on frames for the skylights (to get rid of algae) & make sure the drapes went at least 1/2 to 3/4 shut on the sliding glass door.
All of this stuff was contributing factors for this 90 gal. which was successful. I upgraded to a 125. When I put up the 90 gal. in the next couple weeks I will post a pic with the boxes just so you can see, but you could just as easily try to get a couple 8"x8" boxes to put the lights on & it would give you an idea. IMO 4"x8" would have been a better solution but that might also have required a center piece for extra weight support of the lights. All you can do at this point is get creative.