computer building - CPU recommendation

I have to build a PC to use a desktop application (a WPF one). Then, in this PC I will have to run a SQL Server 2008 R2 instance, host a WCF services project via IIS, run Reporting Services Server and run the application.

Thats why I need to know what processor will be better for these needs:

I can afford: AMD FX-8150 8-core or Intel I5 2500K.

I know Intel proccesors are really fast, but maybe in the future another PC will be using this PC WCF services, and I thought more cores will be better. Sadly, I just find game benchmarks comparing these CPUs.

First off, the CPU probably won't be the bottleneck; SQL, WCF, and IIS are i/o, memory, and network intensive but don't really call for much processing power (though they can benefit from parallelism, which is not the same as saying they will benefit from parallelism). You should worry more about your RAID controller, a good SATA controller (or SCSI if you're feeling old-school), your ethernet card, your bandwidth, etc.

That said, the AMD line you mentioned ("Bulldozer") was designed with power and heat efficiency in mind, so unless you have power and heat constraints that doesn't really help you. But the CPU (within certain reasonable limits) isn't going to be what limits performance here.