Hey guys im new to the page and just bought my first is300. I'm having concerns about exhaust setups. The car is Completely boned stocked.

I like the hks hi power cat back system my question is could i run a megan racing down pipe (y style) with that system on stock headers cat converter and resonator? Or with out a resonator? Maybe someone can give me a couple ideas with that setup with potentially a good ram air intake suggestions. (Seeing as srt is discontinued) I've seen injen being a good quality replacement just not as much power. Thanks folks for any input.