There's a guy right there on Fox Island that pedals metal structures - i've seen him a various trade shows around town and he's very competitive. And there's a competitor in Port Orchard that will help you (sorry, can't remember their name).
These metal building suppliers are quite common in the Puget Sound area - I'd recommend seeking them out first before going through an online distributor. You might learn something off line.
Call him and let me know how it goes:
http://www.coveryourtoys.com/