You don't need to overclock the Intel quad-cores or the 8350 to get good game performance. Overclocking is great for benchmarks, and for helping AMD cpus catch up a bit to Intel in games, but for an Intel quad-core, even the cheapest will provide great general gaming power. The graphics card is far more important for gaming.
You can save money by giving up overclocking and pocket it, or even put it into a nicer graphics card, which will give you more of a gain in games than any overclocking. Or, you can get the AMD cpu, and have the option to overclock, and save money.
My perspective on overclocking is generally that I do it for the fun of it. I've got an older Phenom II 965 system that I've overclocked as well, and honestly 3.4 GHz to 4.0 GHz only shows up in benchmarks and running thermal/fluid simulations in NX. My eyes aren't good enough to look at a screen and say, "oh, I've got 60 fps now instead of 55", you know?