First of all, it will be impossible to find someone to play Tony as good as Pacino did.

Secondly, it would have to be an actor who has already established himself as one of the best around by having obtained at least some several academy award nominations like Pacino had with both GF's, Dog Day Afternoon, And Justice For All, and Serpico too i think. There may be more that I am forgetting.

If it were to be done today exactly how it was done in '83 with different actors, i think a good choice would be Benicio Del Toro. He would just have to have a short hair cut and need to be a little more crazier than he has been in his previous roles. Hes already won an oscar for traffic and was nominated this year for 21 grams so we all kno he can act. The only bad thing bout him may be that he may not be crazy enough to be Tony Montana. He definitely looks like a Cuban tho, hes making a movie where he will be Che Guevara called surprisingly Che.

As for Manny, I think Johnny Depp would be very funny and could also pass as a Cuban with the right hair style. He already played Don Juan Demarco so he prolly could pull off an accent.