thinkin 400 watt mh and hps lights. what brand, what light color, where do i get them? 6 plants

I use 2 450 watt sodium halide and 2 400 watt metal halide and together the work great. The lights were not cheap but I got them on craigslist.
2 totally different light spectrum's but together produce awesome plants.

That would be too much light and heat output.
Try this site.
Not sure what you are trying to grow...
But I have a suspicion this is going to be helpful!
Good luck
~:0)