Look around for an old ratty VX exhaust system where the headpipes are OK, but the mufflers are messed up. Cut off the mufflers and use the headpipes to build a system. That way if it doesn't work out, you've got your intact originals to put back on.
One source for slip-ons for cheap/maybe free is your friendly local H-D dealer. Take-offs from Sportsters work well, and are well built. The baffles can be removed and re-installed, check out Sportster forums for details. Stay away from catalytic converter equipped ones. There's more than one VX running around with Sporty mufflers, on more than one continent too...

Another "ages ago" mod was to drill four holes in the end plate, between the welds. Start small, like 3/16". Work up in size to suit your noise tolerance. If you go to big, it's weld up the holes time. I've never heard anyone who did this say it made the bike run better.

Another was to use a long piece of re-bar, sharpened to a point on one end. Use it as a punch to knock holes through both baffle plates in the muffler. Makes the VX sound blatty like a Honda CB450 with straight pipes, wonderful... Not a reversible mod.
No matter what mod you do the exhaust, it will
never sound like a desmo Ducati...
