Well, processor speed and computing ability will impact FPS in games at lower resolutions. Say less than 1280x1024 in most games. At that point the GPU is no longer the bottleneck and, any FPS benchmarks will reflect on CPU performance. As you hit higher resolutions the GPU's performance becomes more the issue than CPU. You might notice a 3-7fps difference between processors at that point. I run at 1680x1050 for example, since thats my monitors native res.
The review there the guy was running an Engineering sample phenom with an unlocked multiplier(black edition basically), and just upping the multiplier on the phenom to get a higher clock speed. But with the QX9770 he was OCing the FSB, by a fair amount as far as I could tell, QX9770 runs at 1600Mhz FSB if I'm correct? When you OC using the FSB speed, you're also OCing the RAM, and PCI/PCIe buses at the same time. That in turn will have a fair effect on the performance of the system, especially when compared to just upping the multiplier.
If you get a phenom though, wait for the black edition if you can. That should also be B3 stepping. If you don't want to wait, feel free to go get a 9500 or 9600, they don't overclock well, but for the price they're a good quad. At least now they're priced competitively compared to how they perform against the q6600 retail at Newegg.