http://cpuboss.com/cpus/Intel-Core-i7-4790K-vs-Intel-6700k
http://cpuboss.com/cpus/Intel-Core-i7-4790K-vs-Intel-6950X
4760K keeps up with a 6700K, and even the 6950X
This is really the only option, all the other ones have a response time greater than 6ms. However it is a 4K monitor, so you might need to SLI your 980 to get good framerates.
This will tell you which key switch might be your style. Reds are favored for gaming, I went with blues as I like the more resounding click of the keys.
If you can find the model number it would be easier, however this is the current guide for a Sun Quad gigabit ethernet adaptor
http://docs.oracle.com/cd/E19248-01/819-7573-13/1_overview.html