Survive, does not necessarily mean it is doing well. Clams and Acropora can live and survive under darkness, that does not mean that that is long term, nor is that proper husbandry. A derasa is least light needy but even under that much PC it needs to be on top (and it's a sand clam!)
What is desirable is good coloration and growth. You will have the best luck with the Teklight, honestly if you want the best you can possibly get, go for a MH system, I can honestly say that MH gives better results for Acropora, after testing both systems. Yes, the SLS T-5s will work. However, the SLS T-5 system isn't cheap, for that money you could be running a metal halide system.
Find out how much you are paying for electricity and figure out how much the extra power consumption will cost. For me, the difference between running a 96 W Teklight system and a 250W MH pendant came out to be $3.50 per month.
For good T-5 bulbs such as the Giesemann (sp?) you will be spending 25-30 dollars for each tube, multiply that by 4.... you'll spend about 100 dollars every year and a half on changing bulbs anyways. For an MH system you will spend 60-70 for a good HQI bulb every year or so. (8 months is recommended but it depends on how much you run it, I run my MH 9 hours a day)
The only issue that is perhaps of concern is the heat issue, that can however be corrected by a simple use of a fan directed at your water.
SPS is a really silly term, it only gives a general requirement of the coral. I don't know about the Nova Extreme, as I have never used that before, but I will say that Montipora can do well under lower intensity lighting. Whether or not the Nova can provide that, I do not know. If you want to set up your tank for SPS, and are totally sure that you never ever want to get acropora, go for it, they're probably just as strong as PCs. Montis have been reported to do fine under PC, although I would never try it because I want the absolute best color and life from my corals. What you want to try to prevent is deciding to go with the Nova now, getting the Acropora bug, and then having to upgrade again (worse yet buying an acropora to see if it'll work.... that's a nono)
Plan ahead, that's the best advice I can give, have the proper equipment before you buy any animal, and research its needs before you buy, not just for the money but for the sake of the animal. Always.
Hope this helps, and good luck.