My advice to you my friend...
Sell that monstrosity.
Amazing results can occur, but rarely do.
Whatever you do... No rockwool. I would also not recommend setting it up aero style. There are 300 plant sites, but only 150 misters. The top layer in each module gets hit with a fine mist, and the bottom gets flooded. No bueno in my experience.
My best results were when I staggered 150 plants like a checker board. I gorilla taped landscaping fabric over the empty plant sites to block light and allow the media to breath. The media was basically subcool's super soil with about 20% perlite and 20% diatomite rock. I ended up drilling two more drain holes in each module and plumbing them together just like the original ones. I also put screen inside over each drain to do my best to keep them as free draining as possible. I also made my own plumbing manifold with shut-off valves for each module. They got filtered water, with the occasional compost tea.
I vegged for about 5-6 days and the canopy ended up filling out perfectly. Three dimmable 1000's that were at 60% most of the cycle. The middle bulb was MH and the top & bottom were HPS. I would turn one bulb up to 75% about half way through the cycle, alternating which bulb was at 75% on different days. From this I would work up to a constant 2600 watts. The room was sealed with CO2 though, so keep that in mind.
All this effort, after around a year of trial and error, and my results were still unacceptable. The whole design of the thing just holds too much moisture. For it to really boom it out I think each layer of plant sites needs it's own module with a mister at each plant site, and much better drainage. Then each layer needs a pressure regulator, and I think it would rock out some aero.
My results always have been, and have continued to be much better (quality & quantity) with a couple flood & drain 4x4's.
I am working on a more user friendly, organic friendly, vertical system. It's gonna be at least a few months before it's done though.
Have fun with that. You put enough positive energy into anything and it tends to pay off.
Oh yeah... How many moms you need depends on a few things. What kind of lights are over the moms? What kind of space do you have to veg in? 150 or 300 plants? How fast are you trying to get it up and blooming? My recommendation... 1000watts over 8-16 moms.
What strain? Other than the obvious stability and potency... something mold resistant, and short. Keep the clones with nice and dim lighting sitting right on top of them for long enough to get a super stout root system on each clone. If you are doing 300 plants only veg for a day or two, and keep them one single cola per plant. If you do 150 plants, which is where my better results occurred, veg for 5-6 days. If you have a short, single cola dominant strain, then 150 healthy plants with 5-6 days of veg shouldn't need a bit of pruning.
Good luck dude.