Halides suck at making blue light and T5s suck at making daylight. You may want to go blue T5s and more daylight MH (from a watts in vs light out point of view, not aesthetically speaking).
I just upgraded from 4x54 T5 to 2x250 DE with 2x54 supplemental. I went with the DE retro upgrade from Hellolights.com and am very happy with it. If you went with something like a Phoenix bulb you wouldn't need to supplement with anything else.
The Phoenix bulb is many times brighter than my...
As far as leaking goes, my oceanic 75 is 17 years old and no leaks. Original silicon. It has been cichlid tank, oscar tank, and now a reef tank. It was dry from 1999-2006 though, if that matters.
Nothing you suggested was very good. A four bulb t5 setup with GOOD individual reflectors (aquatinics, icecap etc) will be much, much better than your other two suggestions.
You can even keep SPS (higher up) with that setup, believe it or not.
I took a normal clownfish clip and ziptied it to some acrylic that I bent to form a u. I then zip tied that to some PVC (for weight). I just throw it over the back to feed the tang.
I haven't had any issues keeping SPS under 4x54 T5 in my 75.
http://www.reefkeeping.com/issues/2005- ... /index.php
This guy does 8 on a 110 and is almost 100% SPS.
Does anyone make a 12 bulb kit with individual reflectors (required for t5s). If you DIY'ed the hood you are looking at two...