electronic/magnetic ballast
 

I'm in the process of choosing an HQI/T5 light fixture and am leaning toward an electronic ballast. Reduced heat, size and efficiency are areas where I'm thinking this would be a benefit. I'm setting up an Oceanic 58g RR and have limited space for the ballast. For the fixtures in mind, tank size and output (par) (at least what I'm thinking I've learned so far) are not as much of an issue as heat/space. What do you think?

Howdy wildjoe and Welcome to Reef Central!! There are a lot of advantages with an integrated fixture, all of which you have described - researching as you are with this thread is a wise decision.
I have had several different integrated fixtures, the one that I'm using now is a 72 inch Outer Orbit and it has served me well. Some things to consider are, it will produce a lot of heat and if enclosed in a canopy will run even hotter unless properly vented - the electronic ballast is efficient but the enclosed lamps are 99% of the heat load.
Another thing is........this will be one of the biggest investments for your reef, research all your options and buy with confidence............T

Let me clarify. The ballast will be enclosed in the cabinet not the fixture. It will be hung or placed on legs and I will have an open top tank. From my research here on the site it seems that electroninc ballasts run cooler and are more efficient and the two brands in question are Blue Wave and Galaxy. From what I am seeing, some of the magnetic ballasts are comparable in cost to the electroninc so is there really a big difference?