Just throwing it out there, but if you happen to live near a Microcenter you can get a Core i5-2400 CPU for $149.99 and a good Gigabyte z68 motherboard for $50 in a combo deal. Just look for the location drop down at the top of the page and then look for "advertised specials". http://www.microcenter.com/
At any rate, you can also shop Newegg or even Amazon for best prices on these.
At stock speed, Core i5-2400 CPU is only 10% slower than the overclockable i5-2500k.
z68 ASUS or Gigabyte motherboard. Which ever model fits the budget and has the features you want. All are good.
8gb(2x4gb kit) of DDR3 1333 ram. You do not need faster speed since no over clocking. Good brands are Corsair, Crucial, Kingston, and Gskill. You also do not need the fancy heatsink variety unless you just want it. The plain stuff or "value" as it is sometimes called will work just fine.
Video card - The Nvidia 560 ti or AMD 6950 would be a good fit for your needs. They are basically equivalent. Here is a handy tool Nvidia provides that will give you some insight as to what they will do in games. http://www.geforce.com/Optimize
The hard drive will be whatever you can get due to the shortage, but a 500gb SATA III 6gb/s is preferred.
I would look into the Coolermaster HAF series of cases are very popular right now, and also good deals as low as $45 after rebate.
A very good power supply for a single card rig would be the XFX 550 watt. Also very good deals right now.
And lastly, look for a Samsung DVD RW drive at Newegg for around $17. Also good quality and a good deal.