SOG setup help please?

im going to add on to my grow op. Im currently using a 30 site ebb n gro but want to put two ebb n flo trays in my other room strictly for SOG. I am going to have a 53"x53" tray with a 1000w light on it, and a 36"x36" with a 600w hps on it. My main question is what would be the optimal number of plants to put on each tray? I plan on using either 4" or 6" rockwool cubes.

Also any suggestions for dank strains that are 56 days and under flower times? I had the headband but went to vegas for a month and killed the fuck out of the mothers.

thanks for any help

A Very good lowryder strain I smoked was double deisel ryder, hard potent buds done start to finish in that time frame