I’m going to say Debian or RHEL. Both are extremely well supported by software and very stable, but you’d get administration benefits with RHEL that you would be missing with Debian. Since these computers are public-facing I’m going to STRONGLY recommend against smaller distros like Zorin or Manjaro.
Debian and RHEL are proven to be stable for professional work. Debian is especially notable for being on the space station. RHEL is used by basically every company that uses Linux in an enterprise environment.