Upload & Sell: On
How about a first body, then?
Sorry, I couldn't resist, but for most people who shoot 2 bodies, the D7000 would be a nice 2nd body. How about picking up a used D7000 as your second? Some great deals out there, and the best way to think about shooting two bodies, IMO, is side-by-side, rather than primary vs. secondary/backup. Having 2 of the same will also avoid the momentary adjustment due to small differences in the user interface. YMMV.
+1. A number of high shutter count D3's are being sold here for around $1100, that's the price of a new D7000 a few months ago!