What type and make are the motors ? AC servo's use various ways of electronic commutation which is not required on DC servo's making it somewhat more difficult to match an amplifier, also there are two basic types of AC servo, DC Brushless and AC sinusoidal.
Post the make/model you have for more assistance.
Al
BTW a matched AC servo setup is the preferred way to go, due to no brushes, lower inertia and higher max, rpm.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.