They are really nice, I ran a AG Hammer / Hamaguchi Ti pipe on my 600RR race bike last year.
Did you try contacting Sudco? I believe they are the actual importer / distributor for AG Hammer. http://www.sudco.com/
98 Duc 748
05 CBR600RR - Race, CCS #82
60 Duc 200SS
Thanks to my 2007 Sponsors: Two Brothers Honda, Lithium Motorsports, LP team privateer, CBR600RR.com