SSO between Wordpress, Nextcloud and gitlab

I am creating my own home web server at home in order to better control my data. This will eventually be used as a template for the development server (s) for a small startup. The idea is to have Nextcloud for data storage, GitLab for version control and collaboration, and finally Wordpress for the website. I've been looking into possible SSO configurations so that friends / family / co-workers don't have to log in to every application. This will be done using SAML or OpenID.

From what I could see, I could have two different configurations:

• Have GitLab or Wordpress as your ID provider.
• You have a new service / software that will be an ID provider, preferably with a web GUI.

I looked at Gluu and WSO2 for the second option, however they seem to be for enterprises only.

Should I just use GitLab or Wordpress as the ID provider? Or is there simply other software for this functionality that the community would recommend?