Test pipes for my first bolt on!

OhioYJ

If they are non-resonated, there will be no difference in loudness between brands. Resonators will help cut down on noise, and rasp without hurting performance to a noticeable degree.

A cat-back exhaust is by far easier to install for a DIY'er. I did the Berk high flow cats on my 2016 recently, while it 5000 miles on it, the top two bolts on both sides (the ones everyone calls the demon bolts) were the most fun. Everything else was easy. However those two bolts were a bear until you figure out how to get to them and get them broke loose, and then on my car, I still broke the passenger side one. Both my O2 sensors came out no problem, but it's a new car.

It's also worth noting, generally once you get rid of the factory cats, is when you would have the car tuned (when it's recommended). Since you are still running the factory exhaust you're probably ok.