Swirl flap blanks can be bought from eBay, however right now is not a good time to rely on the postal services to bring anything into the country for you... Another strike is on the way, and he haven't even recovered from the last one.
You won't easily find a workshop that will do this for you, as it's more an enthusiast's way to prevent damage occurring rather than regular maintenance. There are plenty DIY's on the net to help you out. I did one too, somewhere in my thread:
http://www.bmwfanatics.co.za/showthread.php?tid=40650