I have had 3 sets of axlebacks on mine. First was the GT500's, much better then the factory set up and absolutely no drone. The sound was amazing, but left me wanting more volume.
I then went with the Flowmaster Hushpowers (now pro series) and they were much louder then the GT500's, sounded deep but had a slight drone around 1900-2200 rpms. Had the volume but not the sound I wanted and drone was a bit annoying.
Finally the Roush axlebacks. They had the sound and volume I was looking for and absolutely no drone. Now that my car is no longer daily driven, only enjoyed on nice weekend days, I'm considering an offroad H for more volume
OP seems like GT500's are what you're looking for