Hahaha, thats definitely a v6 - no way thats a GT. I am currently running a MAC O/R H with a MAC Catback and I would shoot myself in the skull if my car sounded like that.
And to the original poster, the O/R H and Magnaflows is not a good combo - in my opinion. It will be quiet at idle, and its going to give off some machine gunning when you finally get on it. I had an O/R H with Magnaflows (the traditional mufflers) - but I also had LT's. The LT's deepened the exhaust note considerably and there was no machine gunning what so ever. It was a great setup, sounded stock when normally driving and then got crazy when you stepped on the gas.
I heard sound clips of my combo WITHOUT LT's and it was no where near the same. I'd throw them on there for now and save up for a chambered muffler (that are not straight-thru like the Magnaflow's).
I think I am currently on my sixth exhaust setup, haha. I've had two different sets of longtubes, will be going on my third set soon, 3 different midpipes and four different catbacks. I did a lot of mix and matching, so I've heard quite a few combinations. I love the three piece MAC Setup because I can change out my O/R Prochamber and O/R H without having to remove the legs.
Again this is all just my opinion, exhaust is mainly personal preference - go with what your ears tell you kicks ass.
If you want a real sound clip of an O/R H and MAC Catback, let me know and i'll shoot one tomorrow.