Here is the add of the guy in Washington. Looks like a good product
http://seattle.craigslist.org/see/boa/4840784210.html
Bolton Stainless in the interior does custom arches as well as OEM supplied, I believe they make all the arches for Campion as well
google them and give them a call
good point wasnt thinking of the dissimilar metals issueVery pricey and not really worth paying extra to bolt stainless to aluminum. It's always best to try and stick with the same materials if you can