Two famous voice actors have been recently,
* Akira Ishida as "the dashing swordsman" Cavendish
* Megumi Hayashibara as a female bikini-clad gladiator Rebecca
Akira Ishida is famous for his role as Gaara in Naruto.
Megumi Hayashibara should need know introduction for hardcore anime fans as she has voiced, nearly every lead woman in the classic 90-00s era:
* She debuted as various voices in Maison Ikkoku
* Rei Ayanami in Neon Genesis Evangelion
* Faye Valentine of Cowboy Bebop
* Lime in Sabre Marionette J and R.
* Lina Inverse of Slayers fame.
* Female and childhood Ranma in Ranma 1/2
It should be fun to have both of these personalities in a One Piece role.