"Whenever you change the CPU multiplier, you also change the RAM speed. So you're going to have to fine tune the multiplier & reference clock setting to get the best combination. Why not 20 x 200MHz?"
Was this a typo? I was under the impression (especially from messing around with multi vs. ref. clock overclocking) that the only time you will increase your RAM speed from overclocking is if you change the ref. clock, not the CPU multi. You have helped me on my posts and you seem knowledgeable (you're on almost every post I've gone into) so I'm guessing that this was just a mistake.
You have a Phenom II BE dude, there really isn't a need to overclock the ref. clock, and besides, doing so makes overclocking these chips MUCH more complicated, as it overclocks other components as well (as mickliq already stated). Just so that you are aware, my chip (same exact make and model) is running @4ghz as we speak, with a vcore of 1.45 (1.4 is stock). You may, depending on your config, have to bump the vcore as high as 1.5 or 1.55 to get it to run at 4ghz, but then again, you may be able to hit very close to what I managed to achieve. This overclock by the way is only though the multiplier (20x200mhz).
Antec Three Hundred Mid Tower
AMD Phenom II X4 965 3.4GHz @ 3.8GHz stock heatsink
2x2GB G.Skill DDR3 1333MHz @ 7-7-7-21 tRC 28 2T
Nvidia GTX 460 1GB MF'd by Nvidia @ 805MHz Core / 1.61GHz Shader