DIY is going to save you so much money! I was going to say go on craigslist, but DIY would be the way to go if you have the time and wanted to do the work. Oh and that 8 bulb T5 light will be perfect! I have a 6 bulb T5 HO
fixture on my 70 gallon 60" tank and it's awesome. Since my tank has weird dimensions (it is longer than standard 75s), it's shallower. I wanted an 8 bulb fixture, but only 6 would fit and I think 8 bulbs would even burn sps
on the sand! Your light will grow pretty much anything, I don't think it's too much. Just make sure to photo acclimate your corals and move them up 2-3 inches every week to the spot you want them so they aren't shocked and bleached. I've had a favia die b/c it got bleached even when on the sand
but all other lps
and one soft coral are on the sand and doing great. I moved a monti to the middle and it's doing great too.