Current Best bang for buck 55XX or 56XX cpu ?..

Hi,

I am building a game server (DayZ) from one of my C6100 nodes and the advice is that CPU power is better then masses of ram.

Fearing my poor L5520s may crumple under the weight, what is the best 55xx / 56xx series processor for around the US$200 mark currently available (second user).

Thanks
RB