XX Boosted Si XX

I have a 00 SI and getting my exhaust redone soon. Im thinking of going 3" from my turbo back. What do you guys think of this setup: 3" turbo back, carsound 3" cat, 3" piping and then a HKS titanium hyper muffler. Do you think a cat will hurt my setup? Im running no cat right now and im kinda sick of the smell and smoke. Or do you guys think I should just get some 3" piping from turbo back and get a thermal catback? I like the look of my N1 now so I think the HKS turbo muffler would look sick on my car. Any suggestions? Also do you think the cat will eiter break or clog really fast? My car for some reason makes alot of smoke even though it burns only a little oil and is tuned properly with 750 cc injectors and hondata. I was under the assumption that its normal for my built motor to burn a little oil on turbo cars.