Actually, I would not bump the vcore and have never bumped the vcore voltage. I am at 3.6Ghz right now and it is stable without touching the vcore. As long as the under load temperatures stay below 45C it seems the E8xxx series of CPU's will just overclock to whatever you like.
eagl, I ordered DDR2-1200 memory to start with, and started with the memory clock set to at 533 Mhz (534 according to CPU-Z, which is DDR2-1066 speeds). With DDR2 RAM, the clock rate is not always the best indicator for performance. You also have to weigh it against the other settings. Sometimes you can get better performance by underclocking the RAM and tweaking the various other timing parameters.
This is what I am working on right now. I am on vacation this week, so I will have time to get through the testing and tweaks. Once I get settled in and happy with it, I will post my configuration eagl.