Topping and scrog

first, how many clones can i make with 4 (say 40 watt, lumens?) cfls and a dual 60 watt(so 120 watt, and 1200 lumens) flouro tube on top. i am starting them in flowering after roots grow through rockwool cubes because the mother is in flowering. alsso how do u top, and when would i top however many clones i can do with that amount of light i have? in scrog, do u have to tie down the main stem and possibly other branches for it to work properly, or can i just place the branches in the right slot of the screen to get all equal amount of light, or will the main stem just grow past the screen r something? if you must ties the stem, what would you do exactly?