If you need a "real" PGP, GnuPG 2.1 has had experimental support for Curve25519 since 2014. In the most recent version the experimental warning label was gone, so it should be pretty stable by now. Many keyservers still barf on the keys though.
the problem is not that "pgp doesn't use 25519" the problem is the openpgp format as per rfc4880 and the whole thing being from the naive nineties, not suited for advanced adversaries we have since then.