FloPro is what my exhaust guy used to install - they are very heavy duty. He preferred them to FlowMasters.
In the FloPros's 'truck muffler' line, they have baffled and unbaffled, and if you had a cat converter, my exhaust guy would install the unbaffled, as the cat would somewhat silence the exhaust. For non-cat. equipped trucks, he'd use the baffled one.
Any time you put a 'loud' muffler on a large enclosed vehicle (Suburban, Land Cruiser, etc.) you risk loudness inside the truck. On a pickup truck, this noise resonates to the bad, but on an enclosed vehicle, you get to hear it all.