What is the proper wire gauge to use for 220v. Does it matter if you are working between 60hz and 50 hz? Also is there any specific breaker size that is required?

Wire gauge is determined by the amperage load, no matter 120 volt, 240 volt, or 4000 volts, and no matter the hertz.

To add, the Breaker protects the wire or overload, frequency matters on many things, power requirements label will tell 50Hz, 60Hz, both, or selectable by switch.

The insulation resistance matters. Most home stuff is rated for 600 V although you will find some 300 V rated extension cords.

The current that a conductor can handle is generally determined by the material and the cross-sectional area.

As always there are always exceptions such as:

When the frequency approaches RF (Radio Frequency), the power travels on the skin, so conductors are made of tubes and flat bars to maximize circumference.

And superconductivity.