Challenger SRT stock exhuast on Charger R/T

So as my police charger build has slowly been coming along, I've installed srt exhaust manifolds and midpipes, then used reducers to fit them to the current stock 2.25" exhaust to the back of the car. I just recently found a stock srt challenger catback system on craigslist for a good price and im wondering if a. It is a direct bolt in and the exhaust length is correct and B. if there is any benefit going to the 2.5" exhaust. I also have a set of catless mids to fit the srt exhaust and would probably delete the mid mufflers from the srt catback

The car is currently just bolton's with a custom tune from Johan.

any help would be greatly appreciated!:not_worth