Damian, I have an extra stock O2 housing if that would help you get started on the design right away.
I have a feeling that most people are going to want a plug and play replacement for the factory O2 housing that incorporates a screamer. Its probably going to be the most inexpensive of the designs and with the SE-R crowd, well, cheap is what sells lol.
I'm sure that if people want to get the wastegate discharge plumbed back into the downpipe further downstream then they can easily have that done locally.
Something like this that was posted above:
Does anyone have any opinions on which design they want?