No idea which way to go

You need to objectively gather some metrics. A better processor would be a good idea, but “one VM” isn’t really helpful in describing your use case.

Your VM could be running a magic mirror (signage type thing) using close to zero resources or it could be machine learning AI and taking 99% of the system resources.

“Warcraft Server” is a world of warcraft shard? Warcraft 3? OG Dos Warcraft in an emulator?

There are a lot of good builds. I’d go with something you can build and expand like a NasKiller 6 build linked here rather than a proprietary solution.