If possible check with the manufacturer to find the recommended height above plants and what sq ft coverage they claim for your model but in my opinion I think if properly spaced you should have no problem at all. When working with led lights the lumens are more accurate than the wattage. This...
From what I read the spectrum leds throw will give better trichome production and HID tend to give better yield. To me a combination seems ideal. If you have dwc setup I'd run that to gain the faster growth than soil rather than doing both.
I'm on my first run, 5 green crack in a 4x4 tent under 400W HPS. This is week 3 of flower and so far I find the results impressive. Next run I'm going to try to squeeze 6 in because I feel I have some unused space this run.