You are behind the times my friend. There are many above 22% THC . Mama Thai, Wild Thailand, Acapulco Gold, LSD, Tangerine Dream, Blue Dream, Liberty Haze, Critical Widow, Satori, Y Griega and Tutankhmon are just a few. All of these are available at Attitude or Original Sensible Seed Co.
Unless you are growing under lights or starting really late any pure Sativa I know of will get at least 6 feet tall and many will get 9 or 10 or taller. Why do you want something that will be so hard to conceal?
If you want high THC you need to grow well , white russian grown badly might have a crap THC content compared to really well grown lesser known stuff
Not to mention that I've smoked white Russian that tested really high but the high was crap from it. So many things go into a good high besides THC and CBD. I believe turpines play more of a role than most people realize. Some of the highest tested bud is really blah and some average stat buds can give a great high.
Epic fail. There is no end all best. Also why does it matter if you get a really tall sativa when you only want it to grow 4ft tall. My sativas get up to 12 ft tall