Well I guess a plant could get as tall as you really wanted it too based on veg time and the amount of light. If planting outdoors then plants can get tall as hell. Some strains do much better then others when it comes to LST. You do not want to get a strain (for the most part) that states it's great for a SOG if growing using LST. Also, sativa strains can be a bitch to train. Get one that is over half indica.