This is basically my first build, and obviously I'm worried about making sure everything is going to be compatible when it gets here. I've researched a ton but having that confirmed by you guys would help a ton.
Also if you have any recommendations or changes please tell me.
PSU - excellent choice, well suited for SLI / CFbut ya MoBo can't handle it. Either get a SLI / CF capableMobo or drop to a 650.....750 works for CF but for $5 take the 850.
CPU - yes, you're wrong Sandy Bridge is a whole new ball game....Intel designed it to be OC'd and brags about it's OC capability. CPU easily handles an increase fro 3.3 to 4.6 Ghz which has extreme performance impacts.
GFX - Again, can't do CF on that MoBo
RAM - I'd take the low profile Vengeance over the GSkills.
The upgraded heatsink will be mandatory to get the most out of OCing a 2500k. It should get you at least 4.6GHz and more likely 4.8GHz. And yes in the time to come that extra speed will prolong the life of this build.
If you are timid about OCing the asrock mobos have an auto overclock feature that adjusts the settings for you so you just select the speed you want in the UEFI (BIOS replacement), save and reboot. So you don't even have to do or know anything about OCing, just choose 4.6GHz or 4.8GHz, save and reboot. If it doesn't reboot maybe you were too aggressive in your choice so knock it down to the next lowest speed and try again.
EDIT: Oh and yes that XFX PSU is a great unit, especially for the price after rebate. It should handle the system well.