800 watts for 8 plants, will this work?

[stinkyattic]

That's plenty of watts. Go with the HPS for flowering though.
I'm only using 800w total -one MH, one HPS- to illuminate 32 plants in my flower room and they are quite happy, and so am I. Bud density is fine. Don't worry that the leaves overlap a bit. Just arrange your plants so they don't shade each other: shorties in the middle, lanky ones around the edges.