I am considering buying the MSI P67A-c45 motherboard for my i7-2600k processor. Will this motherboard allow me to oc as high as 5ghz? or is there a limit on this model?
You won't get 5ghz unless you have advanced cooling, so the point might be moot. Most p67 boards will net you 4.4 to 4.6 to on good air cooling, maybe a bit higher on water.
Those 5GHz are just lucky thing of only few CPU (batchs), but is almost impossible to know if you can get hose 5GHz on that mobo with that CPU, you only can know that at the overclocking moment.