Hmm!
Well, my concept is of a sort of high-spirited swashy bucklery sort (sans buckler, of course), who gets by with a quick sword, quick wits, and when all else fails...quick feet. If you allow Complete Scoundrel materiel, it'd be perfect for this character.
It could work as either a tiefling or a fey...I'll have to throw some stats against the wall and see what sticks, mechanically...
Fey would be stronger in magic, tief stronger in melee, I think offhand...so what other people do could also influence my choice.