It's been on pre-order status for a long time. Overclockers have this CPU in stock all the time. I'm thinking of buying from them... but they only have max 8GB RAM 3200MHz to offer.
If you really need to overclock and cant wait then you could buy the I7K from OCUK and send it to PCS to be placed in your system. Best call PCS first if you wish to take that route.