since we have this double cat buisness set up...are we gonna have cat back exhausts? meaning from the cat that attatches to the header? or is everything going to be from the axle back?

Everything I am finding is axle back. I am thinking about going to a local shop and have them do a header back system.

but will there be bigger pipe kits available later? or will our only options be non performance enhancing mufflers...

Where are you finding axle backs at? All I can find is the TRD stuff.