Canon EOS400D or Nikon D80 ?

[Guus]

I'm thinking about buying a Canon EOS400D kit (including a 18-55 lens) next month and my choice for the zoomlens is still difficult. I want to make pictures along the track (Six Hours of Spa, Nürburgring Historic Grand Prix) as I did before with my old Minolta.
The Sigma zoomlens APO 70-200 F2.8 EX DG/HSM would be a good choice.
But would the Canon zoomlens EF 70-200 4.0L be an alternative as this lens is 300 Euros cheaper ? I know the 70-200 2.8 lens is the better choice with cloudy and dark weather.

Or would the Nikon D80 kit (incl. 18-70 lens) with the latest Nikkor 70-300mm f/4.5-5.6G AFS VR zoomlens be a better alternative to the above mentioned Canon ?

Is this sensor cleaning-device of the EOS 400D a real advantage ?

Please give me your advice !

[MikeHoyer]

Tough choice, but from your options I'd probably get the Canon with the 70-200 F4L lens. I use Canons and Nikons and can't really find any area in which one excels massively over the other (although I use higher spec bodies), but that is probably the best lens from your selection.