Circle-F is good, but like previous comment, they do take a while in production. Make sure you get someone decent to weld it together when it arrives. For packing only, the piece between the expansion chamber and the muffler comes separate. You'll need to weld it up either on the bike, or clamp/tack it etc.
Pro-Circuit is my other pick. The Chroming is far better than other offerings. Pro-Circuit wont ship direct though. You need to contact Monza Imports. They are a wholesaler, so if you have a M/C shop that is friendly, get them to get on your behalf.
Hope this helps.