Sound is subjective. I think straight throughs sound like garbage. Too much "blat, blat, blat" not enough defined tone. Spintechs are imo the best sounding mufflers I have heard. I run the 9000s on a dumped x pipe and it actually sounds just like my old school 400 that uses flow 10s. And many people agree, small blocks sound better than Ls's. If you are procharged, the best route is a True dual system with your choice of small muffler that will be loud and obnoxious, simply because you don't have room for anything else. Best case scenario is to try and fit 2 spintech sportsman 3000f in the system and maybe try to incorporate 2 resonators if possible. This would have to be dumped. Over the axle you are even more limited. Probably resonators just before tail pipes and maybe either a pair of 4x9 magnaflows or similar size spintechs. Magnaflow will be much quieter at idle but are incredibly boring. Both will drone.

The quietest but decent flowing option possible is likely a Texas speed catback and y pipe 3.5 inches with a cutout. Add a couple resonators or smaller bullets in the y pipe where cats would be. Maybe even a couple resonators at the tail pipes.

 

What is the big deal about what tips a system comes with?? Obviously if the right ones happen to come with your system of choice, GREAT!! But if not, it ain't a deal breaker.
Here is where it gets real complicated- First, cut off the offending tip(s). There, ya did it! THEN, weld on the one(s) you like. BAM!! A system you like to see and hear...