I like WIMA polypropylene capacitors. I have used Panasonic polypropylene capacitors. Illinois capacitor are OK.
https://www.electro-tech-online.com/custompdfs/2008/04/WIMA_MKP_10-1.pdf
If you look at the data sheet for the MKP10 (MKP4, FKP4, FKP1) capacitors and other pulse caps from WIMA you will see graphs of AC voltage and frequency for the capacitors. With a little math you can get from AC voltage and frequency to current.
If you are into math, search for more information on dissipation factor and ESR for capacitors. WIMA and Panasonic have application notes for determining maximum current in a capacitor at set frequency. These notes may be slanted for CRT monitor applications where the current flow is a saw wave (for “S” capacitor)(or 20% duty cycle saw tooth for fly-back cap). There are also application notes on using capacitors in resonate power supplies. There are ways of getting from RMS current to heat in a capacitor. In your case the current is sign wave 100% duty so the math will be simple.
Most high current capacitors should not be used at their maximum voltage rating when under high current stress. (I know this the hard way) Say you put 100Vp-p @100khz in a capacitor and get 10C rise. The pk voltage is only 50 volts. If you use a 100 volt cap that is only 50% of the rating. If you apply a DC voltage on top of the AC, under low stress applications the AC+DC peak could safely get to 100 volts. Under high stress application the PK voltage should be de-rated some. WIMA seem to have this problem more than Panasonic.
I have paralleled up capacitors to increase current capacity. Leave some space between them for air flow. They will get warm in your application. Use large copper traces or planes to carry the current.
https://www.wima.com/EN/pulseselection.htm
Selection of Capacitors for Pulse Applications. This might help.
Capacitors have a “current rating” much like resistors have a current rating. That comes form power loss, heat rise, ESR*current, dissipation factor.
What voltage are you thinking of?