Hello
Personally I think 8s the best way to go. It's such a long process already and that way you can still keep some nice control on it...not get overly crowded. And you've got some nice strong looking branches so they'll be able to support some nice heavy colas.
You're at a good spot to pop a tomato hoop around it too if you like to use those things.
I think the tops are best at 5-8 inches long so definitely let it go another 4-6 weeks.
Good luck with the rest of the grow, it looks great. ✌️