This may not help, but I bought my stainless steel lug bolts from Design911UK < Design911 & PPCGB Performance & Car parts Specialist
sales@design911.com > operating out of Essex in England. Parts usually arrive in 7 days from order - and that's all the way to Australia.
Had them in for 3 years now without any blemishes - check out the website, delivery and pricing compared to the US. I would guess that in your climate, SS would be superior to chrome.....