I may take a re-look at those options...although I want to keep my e-peen at least slightly above average. Do you happen to have an article or two comparing the suggested CPUs to the 2500K that you can point me to?
Google around to find articles relating to them.. Just for the record, the i5 2500K is undoubtedly the fastest among them and also carries the most longevity.. So if you are worrying on the e-peen, definitely go for the i5 2500K.. This is suggested on the basis that you have all other components covered and no loose ends left.. For instance, make sure you have a good amount of ram (min 4 GB), a good quality PSU etc..
You can compare any two CPU's of your choice here -