Google is bouncing back emails to the address you left, but here is my response if you happen to visit again:
Sounds like you have a pretty good idea of what you want. If you want to quickly change shutter AND aperture in Manual mode then the D90 has a rear thumb wheel and front index finger wheel to adjust both. It also has a DOF preview button.
Truth is I’ve never had good luck with the tracking autofocus on my D90. There just are enough AF points to reliably track a moving subject. I shoot almost exclusively in continuous AF with a single AF point selected and the AE-L/AF-L button configured to lock focus while held. This allows me to always have continuous focusing, but I can still lock focus and recompose if needed.
The D7000 would be a completely different story and I’d likely trust it to track subjects for me.
For quick action you’ll be served well by the D90 or D7000. The D7000 has a more sophisticated AF system and can shoot a little faster (6 FPS vs 4.5 I think). About a $450 difference between the two so that all depends on your budget.
Another thing to think about is lens selection. Most of the cheap lenses start at f/3.5 and get to f/5.6 or even f/6.3 in a hurry. Zooms with a f/2.8 constant aperture can easily cost more than your body.
When you say you “don’t need all the gizmos” are you talking about autofocus and metering or things like HD video and other misc features?