DDR3 at 1600mhz is not technically supported by 1155 platforms. It will work fine, but I think it will also void the CPU warranty. It should be fine; there's no way the memory will actually break the CPU, and you don't have to tell Newegg/Intel if anything does go wrong. Tons of people use RAM like this with the 2500Ks just fine.
That 1.5v GSkill Ripjaws DDR3 1600 cas 9 is perfect memory for your Sandy Bridge system. That particular memory probably is just a little older than LGA 1155 so that's why it does not specifically say it will work with that platform. The specs are all good though.
The RipJaws series memory will work just fine. It is compatible with any Intel or AMD platform. With a capable CPU, it can operate at DDR3-1600 CL9 1.50V. The Intel i5-2500K CPU and Z68 motherboard will surely not have a problem.