I suggest you guys to get the 3-eth (big) model. It has more RAM and uses a 15V supply with a standard P4 plug. Other models are powered with 5V, but uses a different (proprietary?) keyed plug. The disadvantage is the absence of a buzzer, I like it. The sound goes out by sound card only.
There are plenty of eBox models, so choose it carefully, matching the specs which you want.