8x series. H85, Z87. Socket LGA 1150. If you are going for the "K" series you should get a Z87, the Z87 overclock (H series does not).
Will work with 9x series motherboards, but not recommended because you will probably have to update the BIOS first. In other words if you don't have another 9x series CPU laying around to update the BIOS the two are likely incompatible.
If you are going new I would recommend the 4690K and a Z97. They are slightly faster, better overclockers, and roughly the same price.