When I lived outside of Orlando there was a place called SKYCRAFT SURPLUS (or salvage). They had all sorts of strange stuff like was found in downtown Manhattan 30 years ago. Electronic "junk" shop full of stuff, good as gold to the right people. Anyway, This place in Orlando had a wall of O'scope, power supplies, military surplus Nicad batteries, meter, relays, screws, and electronic components. Do a Google search and see if they are still there. They may have caps such as these. Remember that caps can be put in parallel to achieve a higher capacitance and they can be mounted remotely with a thick enough wire.