ASIC Chip Availability

[Xenthan]

I'm looking at these standalone chips and thinking I could build my own ~50GH/S miner for much cheaper than buying a pre-made machine.  I have the EE experience to build up the boards myself, but I'm wondering how easy/difficult it is to get my hands on the chips themselves.  I'd ideally like 16 of the new BitFury chips (3GH/S/chip), but it seems like they are in short supply.