Regarding PGP encryption;
We are using www.gpg4win.de/about.html . They name their output files 'gpg', but we just rename them as they are actually pgp files. I like their windows key manager that comes with the product called "Kleopatra" because it simplifies the management of keys. I'm sure there are other products out there though.
When we set up a transfer with another datacenter, we manually send our site public key to them, and they manually send us their site public key which must be imported into our system. (That's where Kleopatra comes in.)