I also have a Magnaflow muffler. There is alomst no drone when cruising. Here's a cold-start for reference for the OP.Check out the Modifications/accessories section, look through some threads and maybe you'll find something you like.
I have a Magnaflow muffler on mine, minimal drone. I can't remember the dimensions on it but I like the way it sounds.
Active Noise Cancellation helps and seems to block out the awe when cruising.AWE 0Fg will get you a good throaty sound, however you will have cab noise. It's not excessive, but you can definitely tell you have an exhaust, especially when you floor it.