Hello ladies and gentlemen.
There is an online Java based game called "Wurm Online". It's a slow pased sandbox mmorpg.
The game is server-sided, but this won't be a problem for professionals like you. I'm looking for a Java coder who doesn't mind to spend his time on creating a hacked client for the game for a certain payment.
If you're interested, please contact me via these services:
Skype: vahinator
Steam: source shift
Email: sourceshift@gmail.com