Is there something that your cameras don’t do that you want them to do now? You haven’t said why you want to upgrade to one of the other two cameras. If these cameras do everything you want them to do I would suggest buying some new fast glass than spend it on a new body. It will make more of an impact on your pictures.
If there is something missing that your camera won’t do, then I would buy the D7000 as it is the newer technology and has a great IQ and take really great pictures. Although there is nothing wrong with the D90, the D7000 is just put out some great pictures. Look in the galleries and look at the pictures it put out.
But if your cameras do everything you want now, buy a new lens that will outlast whatever body you buy now 8 to 1! Then buy a new body when your cameras can't do something you want it to do.