In my experience, the prefab "factory" style exhaust parts (like you get from the parts store by Monroe, etc.) are cheaper than getting custom stuff made up, and they usually fit just about perfect. They may be thinner stock than you could get from a custom shop, but they will last a long time, even in Wisconsin. (I'm from Wausau, a LONG time ago.) You do have to get it welded once it's all put together though because clamps alone will not hold it together and keep it aligned. Can you do your own welding?
I would go with some sort of performance muffler rather than the factory-style strangler. Without a catalytic converter, you can fit a pretty long glass pack in there. I'm partial to DynoMax mufflers which are quieter and cheaper than Flowmasters, but they still cost more than a generic glass pack.
Good luck with yours.
Mike Ahlmann<BR>\'87 Grand Wagoneer <BR>\"Steel Brick\"<BR>Sunnyvale, California