Alright BH.
You're gonna look back at the end and laugh at how easy it really was.
First:
Indica dominate phenotype MJ plants are hybrids ( Sativa x Indica ) that display genetic characteristics leaning toward, in this case, the Indica plant used in the mating process. A Sat (sativa) dom pheno displays more Sativa characteristics. Read up on Indica, Sativa and Ruderalis if you haven't already.
Second:
I would top just BELOW the 3rd node (but above the 2nd) to get 4 nice colas, unless you want the 6 colas that having 3 nodes will give you.
I believe it would be easier for you to manage and learn more visually, instead of learning with a large plant/bush.
See what just 2, 4 or 6 colas does. How they grow. What to trim from the bottom according to YOUR environment and etc..
Check out Weedler's new topped plants. He did it above the 3rd node first, then went back and took another (3rd) node off. Now he just has 2 nodes. Or go look at my last few pics of my Ultimate Chem's on the left of my tent. Those were topped at THE 1st NODE for 2 colas !! My Monkey's on the right were topped at the 2nd node for 4 colas each, and look how the 2 Sat dom phenos on the right bushed out, compared to the lone Indica dom pheno which grew more straight up as well.