You shouldn't use other products with vb. it will only lead to frustration. 4 -6 grams r/o soft, .5 g shine and 1 g +life. if you have cal mag hungry OG's or Chems vital garden has a carbonate based cal mag.
Oh yeah forget about the light rails GB's are set and forget. 4 over each table with 4 straight down the middle. Utilize the crossover lighting of the GB's. Keep tables on wheels so you can move them to get at edges unless you have really long arms.
You won't need 10 gallon pots for coco. You would be better off with 3 or 5 gallon smart pots or airpots 15 to 18 per 4 x 8. 50/50 coco/perlite or 75/25 coco perlite. Drain to waste multiple waterings per day as needed. 3 rows of 4 GB's each. Depending on the strain you may need to trellis for...
Do you have a separate area to veg the beds before flowering them out? If you do beds are the way to go, if not your turn around time will be quicker with 2 gallon pots.
That is a great set up. Realistically I would guess the first few runs will be 2 #'s per bed working up to 3 # plus per bed when you get everything dialed. All strain and veg time dependent. Look forward to watching you blow tis room up.
@irony veg+bloom is a different powdered nutrient. Stick with the 321 just as you described. Yes 321 can be diluted into RO just like regular bottled nutes.