... at the moment I'm more inclined for the d7000, feels better on my hand ,Controls, Af Motor. Just hope the 6400 ISO is going to be better than the 3200 on the d3100. I'm just afraid it won't be a big improvement picture quality from my d3100 . I'm keeping the d3100 as my second body.
Assuming the same lenses used on both the D3100 and the D7000 there isn't going to be a particularly noticeable difference in overall picture quality. The D7000 has better resolution and color depth so technically speaking it's the better of the two but on a practical level you're just not going to see shots out of the D7000 and say, "Wow!". That's just not going to happen. What you're really paying for with an upgrade to the D7000 are some of the prosumer-level features like the AF-motor and the dual card-slots & command-wheels. I don't mean to downplay the significance of these upgrades, they're very, very nice and worth paying for. My point is, you're not going to see a huge jump in image quality with the D7000 over your D3100. What you might want to consider is putting a really nice piece of glass on your D3100 instead of upgrading your body.
Let me ask you this... How "into" this whole photography thing are you? Are you pursuing this as a passion or are you a casual shooter taking shots on vacation and special occasions? Do you shoot RAW or JPG? How much post-processing do you do? I'm asking because only you know the answer to these questions and they are the ones I would be asking myself before dumping a lot of money into this. If you're a more casual shooter I'm wondering if you might not be better off investing in a *really good* prime lens (if you don't already have one) for your current body. You could pop a 50mm f/1.8G or 35mm f/1.8G on that '3100 for about $200 USD and you might be surprised at how just how good the IQ can be out that camera.
Lastly, you have to consider your technique... Getting good shots, and I mean
really good shots, has everything to do with your understanding of your camera, the principles of photography and how well you apply them; it has little or nothing to do with the gear you're using. You might want to consider investing in some education, be it a class or a book or a subscription to Lynda.com to better your understanding of photography.
Just some food for thought from a Stateside Insomniac. Good luck to you with whatever you decide...
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Postscript: Having said all that... Have you considered the D3300?