I'm in the market for an AMD 64 3500 and am all confused about which core to pick. I've seen Winchester ($320 - Retail), Claw Hammer ($232 - Retail), Venice ($222 - Retail) and Newcastle ($270 - OEM) cores. I don't plan on doing any overclocking, so which one should I get? Is there really a difference between them to justify a $100 swing??