I have a 37 (about 24"deep) with the same footprint. My current lighting includes a 150W metal halide and a 24"HO
blue. (Two fixtures) If I had to do it over, I definitely would go with the 250W with 2 HOs built in. With just the metal halide, the sides of the tank look dark and it's too white.
Current occupants include green zoas, mushrooms (3 varieties), bubble coral, green star polyps, Xenia, a deresa clam, and a long tentacle anemone. The clam is on the right side on top of the rock, the LT on the bottom left, metallic blue spotted mushrooms on top left with the zoas next to them, red spotted mushrooms on bottom left, slightly above the nem, green hairy mushrooms dead center, bubble coral about halfway up on the right, green star polyps top center, Xenia just to the right of the anemone. Everything seems to be doing well at the moment with the possible exception of the bubble coral. He hasn't fully opened since a water change on Sunday. (The Xenia used to pulse, but quit shortly after I put them in this tank. I think I had too much flow on them and they quit. Anyone know how to get them to pulse again?)
Before the addition of the blue HO
bulb, I had some yellow polyps, but they began dropping one by one shortly after I got them. I don't know if maybe my lighting was too bright for them and they didn't adjust or if it was too much flow, my shrimp ate them, or what. I also had a bubble tip anemone which decided to live under the rockwork, got no light, bleached and died.
Here's a fairly recent full tank shot with both lights on:
My halide fixture also has 6 blue and 6 white lunar LEDs. They make no visible difference when the other lights are on.
BTW, the rock which used to have the yellow polyps is towards the bottom right in this picture.