Forgot to comment on plant counts for ya Greybeerd.....
In general...4 per sqft is max density. 6" pots, all touching.
You mentioned 2gal pots...at 8", you can fit 3across per 2feet...so a 5ft width = seven 2gal pots/plants

Veg time...strain...topping/scrogging...these are all factors that determine the best choice in plant count.