There are a few dual exhaust cat back systems. Magnaflow 16622, Flowmaster, MBRP, and I think Gibson too. Aluminum or stainless steel, angled or rear straight exits. There are choices. I'm not sure if there is a fitment difference between Quad Cab vs Club Cab.
They are basically a single exhaust until the muffler, then it splits out to dual exhaust at that point.
I put a single Magnaflow pipe, that splits into 2 after the rear axel, and straight out the back. (Both on the passenger side) It's possible to put a true dual exhaust on. However, it would cost a lot of extra money in other mods to get the correct back pressure again. Cat-back is the best option.
I just got a Magnaflow muffler, about $90, and had a local shop put it in with there pipes, for about $300. I drive on salty roads in the winter. So a new exhaust is inevitable every five years or so. Regardless of material used. There are cheaper mufflers, cherry bombs are more like a flowmaster. It depends on how loud or quite you want your cabin.
I put a 2 pipe cat-back on the predecessor to the 3.7 (3.9 V6) idle it was a nice low sound. Got pretty throaty after about 1,500 RPM. A single pipe system is probably what you want. Your right, the power output isn't going to change a whole lot. Even with a modified air intake/filter, it's only going too be 10bhp max. Look at YouTube clips, see what other people did to find what you want.