No worries, the wideband a/f meter is the Best way to ensure you are getting the correct/ideal ratio @ all RPM's. With out it, one is just Guessing.
Magnaflow also makes metal substrate high flow cats which is what I run.
I typically keep the two in/two out muffler to retain the stock look..I don't like to have any tips sticking out, just slash cut and ideally hidden from sight whenever possible.
Andrey is the fellow w/ FGS modules..he can be found here:
http://www.fgsswitch.com/
We chat often, he's a good guy.
I hate to sound Utterly out of the loop, but I'm assuming you mean football cowboys..? I'm completely uninformed when it comes to team sports..however, if you want to chat World Rally, F1, Moto GP, WSBK just about any type of racing that turns Left and Right and I'm game;-)
Jonathan