fuck 12/12 from seed dude, no offense, lol. Just listen real quick bro. GET ANY strain you want to. Basically all you have to do, is top your plant like 3 times, and then about 2 weeks into flower, when shit starts to stretch, start tying main branches down. I did this method, and i ended up with a plant that produced a little over an oz, but the plant itself wasnt any taller than 10 inches, because i tied her down like a motherfucker. check out my top grow journal man. I had a few fuckups with some plants along the way, but two of them were tied down like crazy and tey were both about 10 inches when harvested. If ida untied them n let them grow for 2 or 3 weeks, they probably would have stretched to a couple feet. If you only have a couple feet of vertical grow space, this is your best bet bro.
Hope you have luck findin what your lookin for, n good luck with your grow to come man.
-K1.