ButterflyLabs ASIC is probably your best bet (I've got one on order), but it will probably be several months before you can get one.  They're not really shipping yet and have quite a backlog to get through when they do ship.  I'm not aware of any other viable ASIC vendors, and it would be silly (IMHO) to get anything but an ASIC at this point, so you're stuck waiting for them.