Which protections can I use on the server
All the products / tools you list have a different focus and target different threats/aspects of system security. One is not intrinsically better than the other.
The use of one does also not exclude the usage of any of the others. You can use them in concert to create a limited form of defense in depth.
The only thing missing from your list is arguably the most important, especially on systems directly connected to the internet:
- regularly apply all relevant security updates and bug fixes