SIZE of Pot/Container would limit (or not) Size of Plant, if Indoors. Assuming you do have Indoor Grow; 400W Lamp's; MH and SPS are MORE than enough;i.e.;
Grow-Tent of 4X4X 76" with Adjustable Ballast; 50/75/100 percent Switch produces a whole lot of Light and Heat! I use 50% setting and my "Tropical Strain's" are;
doing extremely well; becoming prolific AFTER Ten weeks; Now beginning (11th/12th week) to Flower with excellent Trichomes. Will continue for at least another month;
with Flowering Stage. AS for "Topping/cutting off"! Personally i would NEVER do that; too risky! Let-em-grow however high they want; Tent height is 76"!!