MSI P55-GD80 with X79 ram

There is no guarantee that those kits or any other kits will work in your system. Your motherboard probably can't run memory as fast as those kits anyway so they would be a huge waste of money.

If your motherboard could run those kits you wouldn't see much performance increase in most applications. Compression.deocmpression is the only type of program I have proven through benchmarking to take significant use of faster RAM and I have been told that rendering also does.

If this is a gaming machine then you would probably like to know that games are not memory-bandwidth or latency bottlenecked and would see little to no performance increase during play. If there is a performance increase it wouldn't even be a noticeable increase anyway.

If you really want to upgrade your memory then you would be best off getting a $100 or less 4x4GB 16GB kit. Kits of that capacity and price run between 1333MHz and 1866MHz (1600mHz very common) and you really won't see a performance increase worth the money of the more expensive kits. Most definitely not since a motherboard that old is highly unlikely to be capacble of running memory that fast and the CPU probably can't either.

After 2 days with no answer, I found http://www.newegg.ca/Product/Product.aspx?Item=N82E1682..., which states it is compatible with P55 and hit the trigger.
Currently stable @ 2133mhz, 9-11-10-28-2T, 1.65v, which are the advertised specs. i7-860 CPU is also stable @4.0Ghz.
The P55-GD80 is one of the boards with the highest overclockability, not sure why you're doubting it being able to run ram at this speed. I've seen reviews pushing it up to 218mhz bclock and running Prime95 flawlessly. (even tho I wouldn't bother going past 210 haha).