If you want GOOD sound, you're right about the Flowmaster 40, but-
Get a cat-back and the sound is sweet, plus you can relocateit and get rid of that big lump on the assend
Here's mine and sound is "HOT ROD", there's no drone in 2wd, unless I make a mistake of trying to climb a long grade, without having the auto downshift and off-road, no drone, just a kewl exhaust sound
I doubt if there's that much difference between the Banks/Magnaflo/Gibson/Borla, but you gotta get the cat-back for the sound difference-
No power increase, just an earpleasing tone !!