Personally, (and that's a key issue here) I'd keep the tree in it's current pic one form. I don't see this tree as a good candidate for formal upright, but it has the makings of a nice informal upright done in the naturalistic style. You're already halfway home if you take that approach.
I also think that you could do a more traditional styling with using that side branch as the continuation of the lower trunk, and (again) personally, I like the scarring and bulbous nature of that branch. But it is a personal taste, that not everyone will like.
So really I guess I'd ask, what kind of bonsai floats your boat? I myself am drawn to certain forms of both types, and try to go with whatever the tree already has as it's best assets.