Your 8 600w hps would cover that space prettywell. I would probably do 3 along each side and 2 in the middle maybe faced perpendicular to the others to even out the coverage. Even the 3 along each side would give good coverage.
let me say three words.
Air Cooled Hoods!
I don’t know why people don’t utilize them more often but it’s absolutely worth it. I did basement grows for 12-13 years in locations that were 90 degrees outside in the summer. I never could afford A/C and things definitely got warm in the basement in the summer, but running an air cooled hood allowed me to get most of that heat out of the grow space and into the rest of the basement to mix with the lower ambient temp air. I was also able to keep my light closer to my plants because it stayed cooler and wasn’t burning them. I usually ran my 1k hps only 14-16 inches from my canopy.
I thought about switching to 2 600w lights instead of the 1k a few times for better overall coverage so you have a good starting point.