Z68 motherboards needs DDR3-1600 RAM, but it's only 8GB (2x4GB) for $50.00ish.
Do you have a PCI-e video card? Or you can use the oonboard GPU of the SB/IV CPUs, if the mobo have display ports. I didn't look.
Do you have (at least) SATA II hard drives?
What kind of power suplly do youo have.
As you can tell, upgrading to a new system means A NEW SYSTEM: CPU, mobo, RAM, Video, PSU, and most of the time, a case.