The bulb I've really been liking is KZ's New Generation (14.4k), so I'd say get one of those. As well having a KZ Coral light 10K would look good. You already have a KZ Fuji Purple which will compliment the other bulbs. I would say getting a Ati blue +, or a Ati actinic blue if you can not find the blue + in the mix would be good (does not have to be ATI brand).
I've been running a 4 bulb 48 inch tek unit in my 125ish gallon tank with the following config and am liking the overall lighting look and growth in the tank (after trying may different bulb configs).

Front bulb- ATI Superbrite (similar to the GE 6500K)
Front middle- ATI Blue +
Back middle- KZ Fuji Purple
Back bulb- KZ New Generation

As I have it the middle bulbs turn on a 1/2 a hour earlier and later then the front and back ones. So with a similar ratio in your eight bulb unit I think you will be more then happy with the results

My experience was that the T5 lights that I had did not grow my SPS corals at all. I don't know why, I just know that as soon as I switched to MH I got massive growth from the SPS that I had at the time.

I have the 72 gal. bowfront.....48"X28" deep.......I run the Aquatinics Constellation which is a T5 7 bulb configuration and love the light. It sounds like your tank is approx. 2" wider then mine....check the light out online.

Here is a link to look at the light itself.
https://diyreef.authsecure.com/shop/...b57d9a7a9a94f2

I started with t5s and zero sps growth. I then went to 150mh and i started to get a little growth. After that i was hooked on sps and i went 250 mh .I guess it just depends on what ou wanr to grow with your lights

I am running T5 TEK lights and its more then enogh light for SPS.
I have good color (pinks ,greens especially) and good growth
The key thing for T5 is good Reflector, if you get cheep reflectors you will NOT get SPS growth.
Tek light has a "W" or seagul wing shaped German made reflector, this is the one you want if you considering T5 HO lights.
http://www.jlaquatics.com/product/sl...C+6+x+54W.html
If you decide to go with MH go with 250W DE because 150 or 175 will not be enough for tall tank.
DE is smaller fixtures compare to Mogul based, also keep in mind heat issues...if your tank is in cold basement you'll be ok but if its not T5 will be your choice or get ready to buy a chiller+ hydro to run the chiller.

I have had a T5 8-bulb Tek light on a 120 for several years.

I get tons of growth on easy SPS (Monti cap taking over 1/2 the tank, Montipora digitata growing like crazy), the Montipora confusa is growing moderately, however a Horn coral has not grown at all. I haven't tried any other SPS. However there may be other factors hindering growth like flow, feeding etc.

I haven't changed my T5 bulbs in 3 years or so, I guess I should.

I read that an actively cooled T5 fixture (like the ATI power module fixture) will give much better light output than a Tek fixture. I don't know if this is true or hype. I believe that the amazing European T5 tanks you see on RC are running this sort of fixture.

FYI the T5 light in the link you provided is the exact same T5 light that I had that I could not get SPS to grow for me.