That's what he's implying, correct. I wouldn't recommend you go any larger than the stock piping which is 2.25, unless you plan on doing some intense mods to your vehicle and completely building your engine e.g new fuel rails,injectors,pistons,turbo etc.
Now it really depends on what you want/like when it comes to catback exhausts or a custom exhaust. If you like the big can type muffler on the end I would recommend the magnaflow. The magnaflow catbacks are pretty mainstream around here.
If you don't want a catback exhaust system and you like the smaller tipped mufflers and not the big can type exhausts you could purchase a vibrant or even a tanabe medallion hyper, or any muffler you want really and just have a shop weld it on for you the ones I mentioned are just common/popular and are of good quality. Since you would be purchasing just the muffler you would have to either delete your pre-mufflers yourself or have a shop do it for your desired sound .
