Low Profile Exhaust Stack vs. Resonator?

Getting ready to have a cab guard fabricated for my 6x6 dump truck, and the muffler stack is in the way. Right now its between the cab and the dump box, so I think we're gonna have to move it around to the side of the truck. Also, the muffler is pretty backed up with debris, so its easy to justify replacing it.

The problem is, I spend most of my time in this truck on ugly little backwoods goat trails, and I'm not really excited about making the truck any wider than it is. Seems like I've got 2 options (but I'm open to input);

1) Get the narrowest muffler I can and run it up next to the cab. So far the best I can find is about 9" diameter, plus the heat shield.

2) Put a resonator or some kind of compact muffler in the horizontal stretch underneath the cab, and then I can just run a stack up the side of the cab. Might create more heat than I want to trap under the cab? Or not?

Thanks all!

Wesco