I need some advice on how many plants i should grow

Hello

I have a closet that is 4.2 feet by 4.2 feet. It has 8 foot an tall ceiling. Im putting a 600 watt HPS in it and, might add a procyon 100.

Anyway, im wondering how many plants i should implement in that system? I am going to do one round in soil then go to DWC in 2 mid size rubbermaids, or an ebb and flow/drip type system in 5 gallon buckets. Would it be better if i grew 4-5 big plants (Low stress trained) in 5 gallon buckets or 15-20 small plants in a SOG or SCROG?

Basically i need adcvice on number and size of plants. Can i get thicker buds and more smoke with smaller SOG style plants? Thanks i appreciate all of the help.