ok, i want a deep tone almost silet at idle and quietish till about 4k.
also how much power could i reasonably expect to lose with one high flow cat instead of a full straight through set up on an n/a

 

I'm running a Bonez Hi-Flow cat right now and I can't notice a difference with it or without it.

I'm not sure about the mufflers.

 

Borla FTW!

 

The difference in horsepower between a straight pipe and a free-flow cat is only about 1hp, that is dyno proven. If you run a bonez free flow cat, you won't sacrifice performance but it is going to be loud.
My set up is a RB header-> Borla XR-1 3" straight through muffler-> Custom 3" single side exhaust-> Magnaflow oval style muffler.
The XR-1 really gives it a nice tone and it can withstand the high temps. I welded a couple of flanges on mine so that I can swap it out with my cat if need be.

 

Aww come on, it's handy knowing when you're anywhere within 3 miles of me.

Anyway, other than the made-for-rotary stuff, most of Magnaflow's mufflers hold up pretty well since they use a mix of igneous rock rather than fiberglass as the acoustic material.

I've got a single and yours is a double, and I'm still quieter than you, so the pre-silencer+muffler combination seems to work pretty well.

 

I would have to lookat Maganaflow again but I Thought they wrapped theres in rockwool and fiberglass on top of the rock wool. I know many others do that as well.