Capacitor

[timmy]

What would be a good sub for a .1 1kv white tubular porcelain cap would a ceramic disc be just as good ?

[bandersen]

No. Ceramic caps drift with temperature and change value with applied voltage. Use a plastic film cap.

[Electronic M]

Mouser and digikey sell 1.6kV Panasonic film caps that are pretty good. If you can get the capacitance you need from one of those that'd be what I'd do.