You can do all kinds of silly things with many guns and extra arms and what have you. If that's fun for you then awesome!
Personally, I'd be happy with just using 2 revolvers. 12 shots between them before the reload, so 2 full attacks based on your attack pattern in the OP, with change in the chamber after. Then you can drop one gun and keep going one handed for the rest of the combat to allow you to reload perhaps?
Big advantage of this is having just two guns makes magical enhancement on every shot much more viable!
Of course this assumes your game is allowing Advanced Firearms, but if so you should be able to afford them at level 7.