Glen, right now I have:
Nikon 50mm f1.8.
Nikon 55mm. F2.8 Macro.
Nikon 28-105mm f3.5.
Nikon- 70-300mm Vr.
Nikon-55-200mm Vr.
Nikon-18-135mm f3.5
SB-800
SB-600
D7000.
D200.
D80.
Curt, I think you already have a nice set-up. I really don't know what kind of photography you like to take but I think you can pretty much do anything with your current gear. Just be forwarned, the f2.8 pro zooms are very sharp and addicting.
I still have my D80 with grip (left picture). I don't know why I kept it but I just let my kids play with it for school stuff. Without buying any other lenses, I would keep the
Nikon 55mm. F2.8 Macro.
Nikon 28-105mm f3.5.
Nikon- 70-300mm Vr + your SB 600 /800
Sell the D80, D200
Nikon-55-200mm Vr.
Nikon-18-135mm f3.5
Nikon 50mm f1.8D
Whatever money you get out of these gear, you can then get a used Nikon 17-55 f2.8 DX lens. If the FX move is too expensive, then just stick with DX. I enjoy using my D7000 too.