2008 Mustang V6

Hey Everybody; Let me introduce myself.
I bought this 08 Mustang brand new thinking it would be my last new car. The plan is to keep it in pristine shape and also fresh appearance by adding after market things little by little as the years pass.
Nothing has started on my long wish list yet. I'm getting a little bored with the stock and had some damage done to my rear bumper so I am beginning now.
I'm trying to decide between
1) repairing the existing slightly damaged bumper, and cutting it to accommodate a dual exhaust I have not bought yet, but want to, this month.
2).Instead to make it look nicer, replace the damaged bumper completely and find a GT rear to put on my V6 2008.
Any ideas out there? Is there anything extra needed to get a new after market bumper to fit just right? With all the other things I want to do to upgrade, I haven't found a bumper yet to suit me.