Ill be using it for gaming, so i might get the 2500k, however i am planning on running two monitors...
I didnt include any cooling/ fans as i have them sorted out
Im only going for the 800w as a precautionary thing, even though it might be abit more than needed, the same story goes for the sound card.
Even if you will be running two monitors, I don't think your i5 2500k will be having a hard time pushing a game+browser, music, skype, all that jazz. Even in an Nvidia Surround set up, you'll want to concentrate more on your GPU than CPU.
Also, 800 Watts is more than enough for your rig, I'd go as far to say it's a bit overkill. I have a 750w PSU, but I was planning on SLI in the future (which never happened...) so I would recommend a 650w at most for your specs.
As for sound card, I haven't looked at your particular motherboard, but most motherboards these days have very modest 2.1, 5.1, or even 7.1 audio built in. If you have a $300+ speaker set then you may want to invest in a dedicated sound card, however, it's not really a necessity.
If you're using it for gaming, definitely take the money that you would be putting into the 2600k and put it into a better video card. There is nothing wrong with the 560 Ti, but there are far better options (e.g. 7850 or 670) that cost a bit more.