This message was posted a while ago by Bob <misiura-at-nccoast-dot-net>, and it
looks like it might have the answer to your problem. The units from Hosfelt
could be used to make a 30kV MMC system with either 10nF for $19.90 (using
10 .1uF/3kV) or 22nF for $26.25 (using 15 .33uF/2kV units, this is what I'm
planning to build).
> The May issue of Nuts and Volts shows a number of large, very high
> voltage, capacitors on page 54. The company is "Resources Un-Ltd."
> Phone is: 800-810-4070, E-mail is: unltd4u-at-m20-dot-net (as of the June
> issue). No catalog.
> The caps are .05/.001/.001 uf at 46,000 volts, $79, .05 uf at 60,000
> volts $69, .5 uf at 36,000 volts, along with some other high voltage
> energy discharge types. The focus of their company seems to be lasers
> and military surplus, so these may be suitable for TC use.
> Hosfelt Electronics publishes a (free) catalog with some interesting
> candidates for an MMC style cap. Their phone number is: 800-524-6464.
> Page 54 of catalog 99B, shows a number of G.E. snubber caps made for
> high current, high voltage, service in power switching products. The
> dielectric is metalized polypropylene. .1 uf -at- 3 KV DC is $1.99 each,
> .33 uf -at- 2 KV DC is $1.75 each.