Where to buy replace potentiometers

Hi, I'm from Argentina, I own An Eventide time factor, I need replacement of Two potentiometers, and I can't get them here... They are the first and the fourth in the top, starting from the left. A fríen of mine is going in this days to Miami, would you be so gente to tell me where he can buy them? Mi Eventide is useless this way, I desesperately need help with this, noone here can fix it...thank you very much, I'll be waiting for your reply.

Regards,

Enrique Bellocq.