Mobo with 4x6gb/s ports for RAID 0

Only AMD chipset based motherboards have more than 2 native 6Gb/s ports.

Intel chipset based motherboards have only 2 native 6Gb/s ports. You will be able to find Socket 2011 motherboards with 4 6Gb/s ports, but 2 will be Intel, and the other 2 will be 3rd party (usually Marvell).

So you will not be able to have 4 SSDs in RAID-0. The best you will be able to do is 2 separate RAID-0 arrays with 2 drives in each array.