The 600 II that the OP is looking at falls into that category, though. They're rare enough that availability is posted as a news item on CR and TDP, and they are still selling out pretty fast.
Yeah, I was gonna say, I completely understand why the OP wants to buy it now and ship later, because if you have a limited window, who knows when it will come back into stock.
Amazon definitely isn't the dealer to do this with; you might be able to talk B+H or Adorama into it, but, more than likely you'd be looking at smaller stores.