Servos and EMC PID tunning.

Greatings to everyone..

I'm just trying to figure out some parameters in EMC.ini file related
to servos. Could anyone suggest anything on what king of servo
motors/ amps should one use with Linux EMC and servo to go card.?
ac/DC with /without brake etc. Another interesting issue is the PID
tunning in EMC. Does anyone ahve any proven methed or program to do
so? Any imput would be greatly appreciated.

Thanks
Peter