The 555 datasheet has recommended limits on the resistor values. As bertus indicated, once you have the basic values you can scale them up or down to find reasonable real-world values.

And:

Why? What is this for? That voltage and frequency can cause a severe electrical burn.

ak

I also have laboratory grade PPE given by the safety team to handle high voltage electronics, so there should be no worry there.

 

What is the peak output current required? Also, where are you located?

ak