I run a server on Linode for my personal home page and a small static other site. I could add the voting-theory server if someone can say how to configure nginx to invoke it, because I am using nginx for my reverse proxy. I would not be happy to switch to Apache. If there’s a third option, someone could pitch it to me. I am at the $5/mo. size, and if the forum requirements ever exceeded that size, I might not be willing to foot the increase from my own pocketbook. But sharing the server could work for a while, for a cost saving.
Even if the forum is never to be on a shared server, I still suggest Linode as the underlying net-connected virtual-machine service. I could participate by doing some of the maintenance e. g. pulling the OS updates once every three months.
I would suggest scrupulous codifying of the procedures for setting up the assembled system from scratch, those procedures to be maintained as scripts with the updates and version control using git and stored on Bitbucket (preferably) or Github.