Final Days help me decide! i5-2500/k

I have the money and I'm planning on purchasing this weekend. Of course I have a few questions/concerns I would like some help on. I don't want to short myself on any parts but I also dont want to buy anything more than I will actually need. I'm not a huge gamer therefore I dont need to play at MAX settings. Other than that the computer will be used for the usual things with the the occasional video encoding to mp-4.

CPU: i5-2500k I would like the ability to OC but its not something I'm dying to do, or needing the extra power. So....would the 2500 be the better choice? It would save me a few dollars between these two and no need for a CPU cooler and the chance of a less expensive Mobo. MOBO: ASRock Z68 Again this is subject to change with the above recommendations. I will NOT sli/cfx.

RAM: 4GB G-Skill 1600 I'm happy with these as long as they work with the components.

GPU:MSI GTX 560ti Again happy here.

CASE:Antec 300 Illusion Only concerns here are obviously space and clearence on the GPU and CPU cooler.

COOLER: Hyper 212+ If needed

MONITOR: ASUS 23"

PSU:Corsair 650w. I'm concerned this may not be enough to continually have enough power, should I be looking at 750w? Also I want a modular or semi psu.

HDD: Spinpoint 1tb

DVD: Asus DVD/CD drive

I apologize about not having links but I cannot get to the Newegg/amazon while at work. (which are the two locations I will order from)

Last thing is how to go about get the combo deals on Newegg. I have never been able to match up any components, they always apply to things I dont need. Thanks for taking the time to look!