Air Show Lenses 2

[ipswichboy]

I'm currently shooting airshows using a Nikon D300, Sigma 120-300 f2.8 and 1.4x t/c but, depending upon future finances, may look to upgrade to a second hand D700 or D3. I'll also be looking to get extra reach, particularly as I'll be going from a cropped sensor to full frame, and therefore am thinking of the longer Nikon lenses (200-400 f4, 400mm f2.8, 500mm f4 or 600mm f4).
Any advice from experienced airshow photographers would be appreciated.