I can second the motion of Boom tubes sounding downright awesome on a otherwise stock exhaust. They are very aggressive and loud though. But I had no drone and no popping though. OP go with the boom tubes you won't be disappointed if you want loud.
i have heard loud mouths on another GT and can honestly say they have more popping and crackling then the boom tubes. The boom tubes have virtually none of that. I have had flowmasters on my 02 GT and I hated them. Mucho drone.