Congrats on your new car...For the tune, you would need a tune if you went for a turbo back exhaust (including down pipe). If you had a downpipe you would get a stage 2 tune (stage 2 is the down pipe and the tune, you don't actually need the cat back portion, but sounds like that is your main goal). If you get a catback exhaust you wouldn't need a tune, it would just pretty much be a sound maker. Stage 1 is just a tune with no mods. Most brands are pretty good, but it really boils down to what sound you are looking for, which is hard to judge unless you hear them in person. Go to a meet, or hit up some people on here who are near you and have various exhausts. Tons of choices.
Good luck and welcome!