Best Alternatives to Black Gate Caps


Does anyone have an idea as to the best cap alternative to the Black Gates that are no longer available?

Specifically 3.3uf 50 Volt.
ehein324
KZ is the "top" Nichicon audio cap, but not available in 3.3uF. I would fall back on the FG or the ES (which is bi or nonpolar). Odyssey Audio uses ES series for their "upgraded parts" amps.
Michael Percy still appears to have these PK 3.3uF 50V BGs.

http://www.percyaudio.com/Catalog.pdf