The Canon guys will tell you Canon, the Nikon guys will tell you Nikon. As neither, I may be able to make a point (or two).
Nowadays (not sure how this went with 35mm) you will choose a body to go with your lens collection, not the other way around. If you are going to buy OEM lenses (Canon or Nikon), then choose a body accordingly. If you are going to buy aftermarket lenses (like the Sigma EX line I'm partial to), then choose a body via secondary characteristics.
Nikon is widely rumored to use Sony sensors. To wit, studio tests like
This one show virtually no difference between the Sony A700 and the Nikon D300. They probably have the same sensor. If the lenses are not going to be branded, it boils down to camera ergonomics (more or less).
The Canon 40D is the other in this class that is popular and compares similarly to the Sony A700, Nikon D300. (And I would recommend a body in this class from your stated goals).
"Stetson" and "VTi" are the Canon dudes. I have an Elan II 35mm but I'll let them dazzle you with the Canon and why you should own one -- which I'm gonna bet is heavily glass oriented (no offense guys, but we non Canon dudes gotta have our fun while we can)
