First thing I'd do before laying down the cash for that system is check with your local Ford service center for warranty issues. 99% of the time, most installs such as a muffler system will not void any other engine warranty issues, meaning, the engine is covered, but not the exhaust of course.
I'd refrain from adding a tuner until after your warranty expires, or you have a chat with a Ford service advisor. Most folks think they can simply flash the stock tune back into the vehicle before taking it to the dealer for warranty repairs to hide the fact that the car was tuned. This was true a few years ago, but the newer ECM's now store data that tells the service person that the ECM was changed (tuned), so setting the stock tune back no longer "hides" this. Some folks have said their local Ford service center maintains the warranty even with a tune, others have stated they have been denied warranty claims because of a tune.
Second, go to some weekend gatherings, and see if you can find a car with the same exhaust (or close) to what you are thinking of buying. Listening first hand is much better than audio clips online. You're planning on a large chunk of money; make sure it's what you want!
"These cars are meant to be driven", so enjoy all of it - not just the look of it when it is all clean" - Carroll Shelby
2011 Mustang; CAI, GT/CS/Boss front bumper cover/lower valance/splitter, GT front rotor upgrade, MPT 93 tune.