Upload & Sell: On
I would take the D3 over the D7000. If you can only take 3 lenses, of course you have to take the 24-70, and the 80-200mm. For the 3rd lens, you just need to choose which you like best to shoot of what's left.
Skip the monopod. I threw mine away many many years ago. Just use the tripod. If you want to, just tie the legs together as one and use it like a monopod....
I don't do BIF, shooting birds in general bores me. But I will say that a really good general rule about anything you aren't familiar with... doing it for the first time while on a photo trip is just plain bad thinking... If you are planning on doing some serious BIF, then you should be practicing now. Go in the Nature and Wildlife Forum and ask for advice on setting up your camera, I know they do all sorts of weird things with remapping buttons on the camera, etc... Now on the other hand, if BIF is something you haven't done before and you are just going to stop and a Bird Park and shoot birds, go do it and have fun... BIF must not really be a big deal to you since you haven't done it before. So just go enjoy the experience and have fun pointing and shooting your camera...