Just so you know, the 2500K, while being a really good CPU, is a generation old. If you get a 2500K and plan on OC'ing, you will need a better cooling solution at the very least.....and not just some extra case fans, I'm talking good CPU air cooler or one of those closed loop water coolers. Don't expect to get too far OC'ing the 2500K with the stock Intel heatsink and fan, it ain't happenin.
While I'm on the subject, the i3-2120 is also last generation architecture....Sandy Bridge. Again, nothing at all wrong with it, but if you are getting new stuff, get new stuff. The i3-3225 is only $20 higher, it has HD 4000 graphics and is the newest "Ivy Bridge" architecture. Pair that up with a new H77 or Z77 motherboard and you have a very budget friendly, well balanced backbone that can be upgraded painlessly when funds allow it.