I am not a big fan of rock wool, it will alter your
nutrient pH. Check out sure to grow cubes or rapid rooter plugs. Are you thinking of a sonic fogger or using "fogging" spray nozzles? A hybrid system that uses both nft and
aeroponics (foggers) is a good set up. Click
here for a pic of a system like this that I had good success with.
God bless and happy growing