I didn't know that myth, it's cool indeed. I used to be in love with Greek myths, I still love any mythological stories ^^
Anyways, on Polish wikipedia it says Fenicians thought of the stars as a pair of goats, and Egyptians thought of two sprouting seeds. But yeah, mostly the Greek myth
If we're trying to get inspired by myths, there are a lot of divine twins or siblings. Or we could get inspired by Mercury... Oh, wait, we have that Hermes set already...
But heaven and hell would be too similar to good or evil set, imo.