Dual Proccesor Motherboards

Dual processors aren't that helpful for a desktop pc. If this is for personal use then simply buy the i7 2600k and high end desktop motherboard. If it is for a server then all means go ahead. Just my 2c. With the extra money you save you could upgrade to a ver good SSD.

dual processors are only for servers running xeons.

why do you need 2 cpus? just get a i7-2600k which should be much more than enough threads and cores for everyday computing and general consumer use.

Don't think you will find much. Most dual configs are for servers so those that you do find will have pcie x8 only. I'd buy the 2500k and the extra that you would spend on the MB put into water cooling and overclock the snot out of it. It's funny, years upon years ago, there was at least a limited selection of dual cpu boards.

Your best bet is a company called Supermicro. They make dual cpu boards.

http://www.newegg.com/Store/SubCategory.aspx?SubCategor...

There are quite a bit. As others have said, you need xeon (opteron for amd) for multi socket systems. And they're not just for servers, workstations also need all the cpu power they can get. With that in mind, you will find most have 16x slots for gpus. However lga1336 is being phased out for the soon released xeons for lga2011. The i7 2011 cpus are already out.