I started with a Nikon D50, then went to the D80, then the D300. I am currently using a new D700 as well as the D300. We still have the D80 for a backup. I usually carry the following lenses in the field: Nikkor 24-70, Nikkor 70-200 VR, Nikkor 70-300 VR, Nikkor 18-200 VR DX, Nikkor 60mm Micro, Nikkor 105mm VR  Micro, Tamron 28-300 VC, Sigma 10-20 wideangle, Sigma 80-400 OS, and a Nikkor 2X converter. I use a bogen 458B tripod With a Bogen mid size ball mount head.

I recently added a Nikkor AF-S ED 200-400 F4. Should be a big help with wildlife.