ESXi doesn't do any form of host level encryption, and you can't use solutions like Bitlocker in a VM (using the proper TPM anyway).
Some of these regulations don't make a lot of sense - I've seen web interfaces with trivial SQL injection vulnerabilities that were "certified safe" under PCI or HIPAA rules because someone had encryption on their database. And of course, said database was configured to key in its own passphrase on bootup, so the encryption didn't actually do a thing. It's far more sensible to place said server behind a physical lock and key.
Backup devices on the other hand should be a lot simpler. Most applications, such as Backup Exec*, support encryption on tapes as they are written.