There is a way to make it sound a little louder if that is what you mean.
To do this mod you have to drill out the exhausts endcap rivets to remove them. Then you would drill 1/4" or 3/8" or 1/2" holes (your choice) in between the rivet holes then add some spacers and fasten the end caps back on. I say fasten only because you can choose to use SS rivets or use a rivnut/ SS Allen head to remount the end caps.
You could also use a long rod that has a sharp point to pierce the baffle that is down inside the muffler. I don't know much about this way, and the sound.
I used 1/2" holes in my stock exhaust and it sounded a slightly better but there was no performance gain at all. Drilling the exhaust will also make it run a richer so you will need to compensate for that.
not many 'aftermarket' systems look as finished as the stock exhaust does. (taking away if you like the size, sound etc) but exactrep or any of the european stuff i think looks the best, but they're just slip ons.
like gamorg02 says, you ain't gonna find much with that kind of criteria. have a look and listen to the soundfiles at this link. i think one of the Super Trapp variations or the Over Racing Focker is your best bet (as far as retaining that stock look), but i dunno how much luck you'll have finding them , or most of the others for that matter.
i've been researching an upgrade myself and have landed on the Marks, but it won't be for a LONG time. in the meanwhile i have done the 5-holes that redbone describes, which is definately louder:
if you are looking to upgrade the exhaust "in general" i think you have to prioritize you wants: cost vs sound vs performance
if cost is your #1 priority over sound and performance then any one of redbone's descriptions is the way to go.
if sound over cost over performance, then slipons (i'm sure there are a few fellow vmaxxers who would differ in opinion).
if performance is what you want, then based on the forum it looks like Marks, Holeshot, or Kerker; but you'll have to decide if you want 4-1 or 4-2 and if you want to retain centerstand.