Hey Fleezy, so. For starters.
1.) Be careful with starting seeds in rockwool. It works, but you really need to make sure you run alot of water through it before you go throwing you expensive ass seeds in there...Why? because rockwool comes to you basic,, meaning a very high PH. You need to run alot of water through it to make it neutral B4 planting any seeds. Also you may notice "rockwool wash" products... they are bullshit. Just flush with alot of water, or if you are using cubes dunk them over and over, changing the water every 20 dunks.
2.) LIGHT. You should be using the blue t3 bars for the seedlings, thats best. They will rage real hard under them.
3.) As far as your propagation method. you really should just grow mothers in soil, then clone from them. I have found this to be the easiest way to keep genetics going for a long time, and also if you make several mothers of one flavor, you can ensure that you will have enough cuttings to fill the system in flushes, so that they are all from the same batch of clones. Making mini mothers is a good way to do this. Take your first 3-5 clones and grow them in soil in the room you are going to set up this system in. This way you can get these girls under the 1 or both 600's to make all of this happen AS FAST AS POSSIBLE. Wait until these mothers are like 6" until you put them under your HPS. When you do make sure the lights are as far up as you can for the first few days to let them harden, then lower them so you don't burn them to shit. After a few days witht he lights real far away you can lower them and these mothers will really rage. Top them also, as in cut the top off so that they will shoot more side branches, you can use this top too as a clone, so when you top them get all the tops in your cloner asap.
let me know any other questions you have . . . my best advice is go slow with the nutrient. if you follow the directions on the nutrient you bought. you will kill your plants. get a meter, and never let it go above 1700ppm and you will know you are ok. PH you want at 5.8 in hydro. 6.7 for the soil
Shmaaaa