Can you clarify what you want to do?
If by “hosting Axure prototypes”, you mean using SVN to team projects, then you will only be able to do that with Axure 8, since SVN support has been removed in Axure 9 and only Axure Cloud is supported.
If you mean simply hosting the generated HTML prototypes, then all that’s needed is a HTTP server (Nginx is fine) and some way of getting the HTML files onto the server (I would recommend using rsync, as things like FTP or Samba don’t handle large numbers of small files too well). No database needed unless you want to do something fancy like managing user account access or some such.
My last point about rsync reminds me that several years ago I posted a HOWTO here about automating file transfers from Axure to a web server. Dunno where that’s gone though but I’ll see if I can find it.