If not going to OC, you don't need a 2500K, a normal 2500 is identical at stock speed. (edit, I Just saw that this is a combo package. check first to see if it is significantly cheaper to get the non-K version, it might not be if that package is discounted enough)
Get the DDR3 1600 kit if you can for the same price. It will offer a tiny bit of performance in some scenarios, but at the same price why not?
What resolution is your monitor? That video card might just be overkill
If you do get that video card, make sure the PSU you have is good.