Hi Chris, Delkin Sensor Scope was a good investment for me. This link takes you to Scope & Cleaning Kit:
http://www.fotosense.co.uk/shop/Delk...D=5157&tabID=2
But the best cleaner is not to change lens in poor environment. If you have to - try changing lens with camera and lens in an old film changing bag - Your not after a good light seal but a reasonable environment around the change area - so you don't have to get them all inside - just the gaskets/flanges.
As for your 80-400 Nikkor - I have that lens and find it great in all that I use it for, but I mainly use Shutter priority at Min 1/500 s whatever the focal length and always tripod/monopod or beanbag support. If going Close up I switch to a 105 micro Nikkor or 70-200 f2.8 VR with short extension tube and Monopod.