NAPA, are the Bosals a “premium” unit?:
http://www.napaonline.com/masterpages/NOLMaster.aspx?PageId=470&LineCode=BOS&PartNumber=287323&Description=Resonator+%26+Pipe+(Bosal)
You could get a pacestter and know that it will last 2 winters, 3 if you are lucky.
http://www.pacesetterexhaust.com/monza.php
Or spend the money for something stainless, I didn’t find anything right off, and don’t feel like searching either. You best bet would be to look for a 200sx SE-R stainless exhaust and then have it extended if necessary. (the coupe and sedan are showing the same wheel base though)