Some of you might know I am working on an isometric game engine (currently hosted on github (https://github.com/JeremyWildsmith/JevaEngine
[I'm currently in the middle of code refactor that changes some of the api so I advice against doing anything with it right now]).) I am looking for a server to host ~20 users and preferably quite cheap on hosting. You can get a listing of the basic networking benchmarks I've performed here: https://docs.google.com/spreadsheet/ccc?key=0AslAio6c5EhhdG5RNWNNYVJUZm1oNGI2dW9Cc09nWlE&usp=sharing
That is essentially the average load per user on a server with ~150 complex server-side entities (like NPC Characters etc) The overhead of these characters being user controlled is very small, its just that for every client, the more data has to be sent out. Very little data is actually received relative to the amount sent on the server-side.
I will also be hosting a back-end MongoDB (not required, but it would definitely be a plus to get it in there.) I know MongoDB is optimized to consume many system resources so I'm not sure if that would cause complications. Obviously if I could get an HTTP servlet in there that would be great, but again, not required.
The server would be deployed as an executable JAR. The idea is to periodically push the latest server component of the game to the server. Any suggestions?