I don't know how disease-resistant these are, but they might susbtitute for Purple Cherokee:
Vorlon - OP, Mid-Season, potato-leaf, purple-black, smoky taste, blander than Krim
- - - - - - "Stabilized cross between Cherokee Purple and Prudens Purple"
Black Krim
Kardinal Tshyornyi
Black Prince
Black Russian, dark red-black, mahogany red, Heavy producer and early
- - - - - rich old fashioned complex heirloom flavor, sweet taste with spicy and smoky undertones