I finally got my parts from MTM. Basically they design their catback to directly connect to their 2.75" down pipes and also provide adapters to go from oem down pipes to their catback.
I did not want to modify my oem down pipes or the MTM catback and thought the $125 that I paid for the adapters was worth it. It took three weeks to get them to my house.
Now I have to decide if I am going to do the install or just go and have them installed. I will get a price on it and then make the decision, more than likely will have a shop do the install as it should be about $200.
Will have to take video of before and after to see if there is any difference.