As long as you can run a webserver on a device and fulfill server requirements, it can run... It does not require a specific hardware on the server, of course more cpu power and ram assigned to the servers will give you a better performance during runtime.
Disk space depends on specially the database size, files on the server (phpvms v7, themes, modules etc) will not need that much space (say maybe max 100 mb for them), rest will be database space (which will be dynamic as you can imagine).
If you did run apache, php8, mariadb etc. on your Raspberry device before, why not doing the same for v7 and start testing Basic requirements are listed here
Good luck