Yes, it's the first Tuesday of the month in Carrickmines. Joe is based in Greenogue Industrial Estate, and really does know his stuff. As for suppliers of Milltek, try Keith in Alloy-Wheels based in Blanchardstown, IIRC they supply (and fit) Milltek exhausts, along with other mods.
If you want to hear the full Milltek with sports cat, let me know and you can have a go in mine, although the diverter valve needs replaced.