Hi guys. I've been running a casual minecraft server for me and my buddies on and off for a while now, but now I want to set up a dedicated machine as running a server and the game on one machine sucks ass. I plan to build my own box as I have experience w/ it. It'll run ubuntu server edition + craftbukkit ofc. What kind of specs would you guys recommend for a 24/7 20-30 player server? Looking to keep price and more importantly energy usage as low as possible. Thanks in advance!