well i could get it for 375 with water cooling that keeps it at -2 guaranteed 5 ghz
The laws of physics wont allow water cooling to cool the processor; 1)lower than than the ambient temperature in the room 2)too any temperature lower than the freezing point of water. If thats what you've been told you've been lied too. I also doubt 5Ghz is guaranteed.
To answer your original question it depends on what you're looking for. The e8600 is dual core and the phenom is quad. The 8600 will overclock nicely and handle any game out there. I'm sure the phenom will flex its muscles in applications that are optimized for 4 cores. I would say go for the 8600 because its out now and has well documented performance.