For anyone who is interested, I called Sho Shop to ask some questions.
1. The y-pipes with cat are in stock, so not wait.
2. I asked about the hi-flow resonator they have and why it is $119. I was told that this is a prototype project. Apparently it is something completely new. Details will be posted on their site in about a week when the kit is ready.
I might take the bait and try it as long as I am ordering the y-pipe.