With the quantum boards you could run all 4 and get rid of the 600 watt. The space is only 4x1.5 or is it larger? If it was me I would build one fixture depending on your grow style. Do you have a pic of your space? I was initially going to run the QB132s x 12 in a 4x4 but the cost is a bit more than I was willing to spend at the time lol.
I don't know much about Ecofarm but UV and IR aren't practical in terms of efficiency yet to there to be true streamlined diodes. Agromax makes UV t5 bulbs that would be my preference for UV distribution.
It's up to you whatever you choose though.