As far as the SLP pulley is concerned, I'd call them for the size. I don't know of anyone running one.
Catbacks for our cars don't exsist. If you want to do exhaust work, you have a limited choice of headers and downpipes, but beyond that, you're on your own. There are a ton of combos that people on the forum have developed. Based on your level of performance upgrades, budget, etc the possibilities are endless. Ask around and you'll be able to formulate your decision based on the experience of others.