That's good! The three One Piece characters that I play are Jinbei, Blackbeard, and Brook, though I'm less confident with Brook. (Blackbeard, obviously, doesn't mesh well with most OP characters, but he's such a colossal ham that his voice stuck with me)

If you want to try anything with them, I figure general adventures would be the better fit. I'll add you on Plurk - my username there is megadoomer.