Where to find Black Gate 1000uf 25V caps?

Parts Connexion Has Black Gate FKs listed in 1000uF/50V, which would be an excellent option. They also have 1000uF/25V in the "standard" Black Gate. (http://www.partsconnexion.com/t/catalog/CapacitorsElectrolytic.html) Click on, "Black Gate", at the bottom of the page.

Michael Percy sold the NX 1000uF, 25V caps for $12.50, but- they are long gone. Like anything else that is highly desirable, and no longer in production; expect to pay a premium, if you can find them.