RE light fixture...
FWIW, I use an "industrial" 4 bulb fixture on my 55g. The advantages were clear: the price was very competative [ particularly when purchased new], and the ballasts are [ in general ] beefier. The disadvantages are they can look "industrial", and it may have to be wired, but wiring is very simple.
Make sure to test them before you buy.
I am constructing a canopy for my light and fixture, I will follow up with details at a later time.