Question about Clones from a flowering Mother.

Tomorrow, I plan on taking 2 clones from my plant that is probably a good 4 weeks into flowering. Im going to do a SCROG stealth grow or a LST and Im trying to keep my plants about 15inches tall.

I Have two questions, however:

After I the clones are rooted, should I leave the light cycle on 18/6 and let them grow a few weeks, and because they are still in flowering, as soon as I change to 12/12 they will flower? Or will the clones continue to grow on 12/12 and I should just go to 12/12 as soon as they are rooted?

Second question would be, in a stealth grow with demensions (LxWxH): 15inx20inx20in what would be more suitable yield wise, SOG, SCROG, or LST?

thanks guys