4x8 eh? The best bet for you would be to run 2 hoods.
One for each 4x4 area.
A square hood (2) will do far more you then any Raptor or XXL style hood as you don't have the area they cover......Their for open area growing in large rooms...
The other thing is you most certainly
don't need 8 inch cooling lines for that. Remember that the open area for these lines
reduces the reflected light! So then, 6" lines will be all you need.
I suggest these very strongly.
https://4hydroponics.com/blockbuster-reflector-6-inch-air-cooled-with-cordset
In a 4x4 area, 600w will work out for you well. You can go 1K's but the heat and cost to run increase vs results. Brings you back to 600's.
Doc