2500k is a good choice. It's got great potential to overclock with a 30$ CPU cooler like a CM hyper 212+. It out performs pretty much all AMD CPUs in gaming. I currently am using AMD and it's started to bottleneck my GPU in BF3. I'm actually switching to intel once I get the money for a new motherboard. The one thing AMD did great with their new line of FX processors is the multi-threading. So maybe later on in the year we will see more programs using multi-threading, and then maybe the FX series can outperform or perform the same as Intel. Also, the 1100t/1090t are sometimes on par with the 2500k (which is only a quad core processor), but ever since the failure of the FX series processors, the 1100t and the 1090t (they're the same thing except 1100t is clocked 100mhz faster) are now sold out so that's why I'm looking to get the 2500k.
As for the server hosting, you could use a 70$ CPU to run it with no hiccups with that low amount of people. It's got a lot to do with your RAM.