Planning for First time SOG, questions

OK, question about a SOG grow that I want to start next month. I am going to do a grow using only 2 plants per square foot, have seen as many as six or as little as 1, but I am going to try 2. It will be in approx 12sqf. I will be using 800w of air cooled hps. I want to grow the plants to a max height of 32,- 36- high. I am thinking about growing Champaign, or a NL f5 from Joey weed.
Here is the question,
With almost 3ft of height, do you think that it will be necessary to go for the single koala pruning style, cutting off most of the lower branches, or should I just let them grow naturally with a little stem pinching if height becomes an issue?
Adieu

Any SOGers opinions?