d7000 & kit lens vs d5100 and tamron lens
buy the D7000 and 18-105 kit if you can find it.
sell the kit lens, it's an ok lens if you want to just keep and use one lens for everything, but it's slow and nothing special, it's good tho.
You can sell it for $200, then buy the Tamron 17-50 VC (add $300 more)
altho reviews praise the non-VC, just go with the VC option, it's much better if you plan to use the camera for making handheld videos (it has a nice manual zoom ring in front of the focusing screen, so you can hold the camera by the lens with 1 hand and focus with the same hand as well, it has a nice smooth travel for manual focusing)
The D5100 is nice with the 17-50mm, I have it, but it feels imbalanced, makes the camera too front heavy... simply adds some weird discomfort if you know what I mean.
So my advice if you plan to go for cheap but good is:
Tamron 17-50mm 2.8 VC
Nikon 70-200mm 2.8 VR1 (buy it used for 1k, does 99% the vr2 does for less than half of the money
^ With these 2 you are covered for 99% of the shooting scenarios.
Later add 10-24mm (I prefer it to the Tokina 11-16 because it goes to 24mm) or 35mm 1.8 prime.