Hi Wayne,
Check also with Wima's (Germany) MKP4 series. Mr. Crawford use's them in the Kurre 4 speaker. I never used them, I know were to buy from Wima distributors, but I don't know the price or quantities. He used Solen's bebore in Legend Acoustics speakers. As he says: "...I find capacitors frustrating because although I can hear differences between different capacitors I cannot measure any differences." (in Australian Hi-Fi, equipment review)
Best Regards