I want to add some T5 to my 5' 150g tank. Presently I have 2 250W DE fixtures. Lumenmax 3 and a Reef Optic (Thx Ian, Love them

) But theres some 'holes' in my lighting I think. 3 lights would be awesome, but dont want the added heat/power consumption of another 250W. I was thinking what if I added 4 24" T5 bulbs? 2 in middle, and one on each end? Going across tank, front to back. Do you think they would spread enough light? Problem is the 5' tank, and lighting the ends. If I go2 48" T5's lengthwise, one in front, one in back? There leaves 6" on each end? WHich might not be bad, considering I am going to have a "floating canopy" style light hood. Building a box around all the lights, which then will be hung above tank, from ceiling.
Any insight on what would be better, light and cost wise, and what part's I should be looking for, I'm all ears

Tank dim's are 60"l 24"d 24"w
Thx in advance