Sadly, I only know what the output of the transformer is as well as the input voltage (120 V AC) and input frequency (50-60 Hz) is. Beyond that, I am only certain of a center tap being present.

   All 12 diodes below are rated to have 30 kV and 100 mA go across them. The current rating is so high because I am expecting a ~100 mA surge to be present for about 2 seconds max. Since the diodes are also rated at that exact current, should I be looking to find diodes rated for a higher current, or is this acceptable? Also, is the 30 kV rating for the diodes acceptable as well?

    By the ammeter (which is a Southwire 10030S Multimeter rated for 6,000 volts at 200 mA), there is a set of 5 resistors linked in series, each having a resistance of 20 ohms, a power rating of 1 watt, and a voltage rating of 20 kV. These will serve as the meter shunt and shall go directly between the probes of the meter. All of this is attached to the center tap line. Will this provide proper protection for the multimeter/ammeter, which would otherwise be rated for 6,000 V?

    As a side question, would the type of resistor matter for this set up? I was considering either using carbon composite or metal film resistors due to their lower cost.

    After the ammeter, I have a Fluke 80k-40 meter connected to an Innova 3300 multimeter. This will allow me to safely detect the voltage going through the circuit.

    The 60 k Ohm resistor serves as a ballast resistor to dissipate energy in the case of a significant current draw by the source. It (also with the rest of the system) will be submersed in mineral oil and transformer oil.