Hi pbekkerh,
I bought some a couple of months back from:
http://www.mfactorywest.com/
I emailed TZmike@Mfactorywest.com.
Fantastic silencers. look & sound great, brilliant build quality and reasonably priced. I went for the 250mm.
If you have a look on the second page of the bike snaps mines headed up Mark's nsr
regards
Parky