Just reread your post.
The default is for both kits 1.5v and this is correct for a Sandy Bridge build. The RAM will default to DDR3 1333 speed and you will need to change it in BIOS to DDR3 1600. Very easy to do.
If you have not bought it yet a Z68 or even Z77 motherboard would be a better choice. More features than the P67. There is nothing wrong with a P67 and I have one but when I built this computer P67 was the only choice.
This explains the different chipsets.http://en.wikipedia.org/wiki/LGA_1155