Well waiting until April might be a good idea not just for Intel's new Ivy Bridge CPUs (the biggest advantage there will be even less powert consumption rather than great performance increases while small speedups most certainly will be there) but also because of the new GPU generation. AMD currently is releasing their (currently overpriced) cards and will have a complete portfolio out in March while NVIDIA will start pumping out new cards (which also will be in the price region of your interest) in April. So unless your need of the new PC is really urgent I'd wait...

If you're interested in overclocking choosing an Intel CPU is even more appealing because as Rei already said there is a huge clock potential Intel doesn't use (in order not to totally crush AMD) giving you potentially 20-30% higher performance when overclocking. You want to go for the CPUs with the "K" ending then as those can be easily overclocked by setting a multiplicator for the CPUs clock the way you want it. As you're aiming for a gaming machine I'd stick to the i5 CPUs as the i7 ones with their HT technology, which simulates additional cores to make better usage of the cores really there on the chip, are of next to zero use in games (and sometimes even counterproductive). So save your money here and stick to the i5 processors...

Also another tip for your RAM: First - do you really need 16GB? Apart from Battlefield 3 I know of no game that can really make use of more than 4GB Ram thus making a set of two 4GB modules (i.e. 8GB total) a perfect set for the foreseeable future. Also stick to DDR3-1333 Ram as faster modules won't give you a higher performance with today's processors. You also should check that they run with 1,5V voltages as higher ones can cause trouble especially with Intel systems. I'd also recommend not to buy modules with fancy heatsinks. They are not needed (unless you want a window in your case and something neat to look at) and can interfere with a better CPU cooler which I'd highly recommend not only in general for noise reasons but especially for cooling an overclocked processor (the boxed cooler that comes with the CPU just gives you the bare minimum in both cooling performance and noise level). I could recommend some CPU-coolers but there's something to think about: Those things got quite tall today so when buying a new case you should check if it gives you enough space. So could you write down what case exactly you were thinking of? "CT 1014 GAMING ATX PC COMPUTER TOWER CASE" doesn't say much to me. Is "CT" the vendor name? I know CoolerMaster but that'd be CM - apart from that "CT" might stand for Chieftec but you really should type this one out...

Oh and apart from the graphics card talk that happened until now - for a good gaming system you don't really want a GTX 560 because that's really no good graphics card. Even without waiting for the new cards coming in the next few weeks you can get a far more performant card without paying much more (especially when e.g. using the proposed savings on the motherboard and RAM here)...