I spent a while thinking about what I'd want out of a swashbuckling character, and I came up with a concept that's a very different spin; it doesn't even involve the Duelist or Swashbuckler classes. I think it meets this requirement, though:
This character would (more image stuff) be able to quickly close the distance, then be nigh untouchable in combat as he dances around, aloof and secure in his ability, getting consistent criticals (rapiers do that).
Try a Rogue 4/Fighter 2/Dervish 6. The Rogue levels give you the foundation of acrobatic and social skills, the fighter supplies the bonus feats you need for a specailized combat class like this, and the Dervish is your constantly-in-motion, nigh untouchable, flashy combat character. If you're using 25 point buy, give your 12th-level character Str 14, Dex 16, Con 10, Int 12, Wis 10, Cha 12.
Me, I'd probably do things a little differently, because when playing a swashbuckler, the social skills are as important as the combat. I'd take an extra level of rogue, and as a pure style decision, I'd use a cutlass instead of the obvious scimitar choice. My character would look something like this:
http://www.coveworld.net/eberron/dervish-swashbuckler.gif
He'd focus his rogue skills on Bluff, Diplomacy, Jump, Sense Motive, and Tumble. He'd wear leather (maybe studded). As far as roleplaying goes, he'd be your standard honorable scoundrel, though his upper-class pretentions would be a charade. As opposed to the calm and collected Dorian Gray concept, my take would be a bit more brash. He'd also turn his nose up at dungeon crawls, far more interested in the high seas or the world's greatest cities. Actually, this is one character that's a pretty natural fit for my own personality ...though in that case a 12 Charisma might be a bit low.
.
