I know you want a good sounding exhaust system, who doesn't? But since you live in Salt city Michigan, why not spring for a good sounding exhaust that will last forever? It doesn't make much sense to buy anything but Stainless Steel in the area you live. Sure they cost a little more, but it will be the last system you will ever buy for that truck. If this sounds like it makes sense too you, as it does me, I would recommend the Hog Performance SS exhaust system. It is made from 4" 304 stainless, has a true 4" down pipe, and comes with your pick of three (3) different mufflers. You choose the sound level you would like, I went with the quieter version and it sound nice to me. Also the system comes with a killer 6" x 24" SS tip that gets everyones attention, it looks like a howitzer tucked up under the truck.
I suppose you will do what you feel is right for you, I just wanted to alert you of this possibility. The cost is very competitive with other non-stainless steel systems, it usually sells for around 550-600 dollars. Not that bad compared to other non stainless steel kits, and a steel when you compare it to other stainless steel kits available on the market. Also Hog Performance is one of the only exhaust systems to come with everything stainless, all hangers, nuts and bolts and even stainless band clamps, which most don't even offer in non-stainless. I think it is a real bargain, I have had mine for about a year and love it.