Gitlab is currently on major version 14. This needs to be updated to the current version 15 release this summer, regardless of the repository storage option chosen
Gitlab has deprecated support for direct repository storage where the repositories are stored either locally, or through and NFS share, and gitlab accesses those directly. The new model of repository storage is to use Gitaly, which provides high-level RPC access to Git repositories. It is used by GitLab to read and write Git data.
This option would keep the existing method of repository storage with git repositories stored on the SoCS File server and served to Gitlab using NFS. This is not a realistic long term option, but may allow time to make a decision and purchase any required hardware.
Using the existing gitlab omnibus package, enable gitaly on the current gitlab server and migrate repositories to being hosted locally.
Use the current gitlab server for most gitlab components, however install gitaly on multiple servers (minimum 3). Repositories would be stored on as many servers as stated by the replication factor.
Gitlab offers instances of the software hosted by them