Of course not. The d40 and D40x models are very similar to the d60, but it still has a lot of features that we can't find on a d40, as d-lightning, lens cleaning, stop-motion movie, etc. If you are talking about picture quality, it is very similar.
The d60 is better. Buy this one if you can afford it. If you don't, try the d40 then. It has less features but still has great quality.
The D40 has less megapixels but is better at high isos, so is more sensitive.
They are virtually the same same; they have the same dimensions, the d40 is slightly lighter.
You can buy a remote for the Nikon D60 but not the Nikon D40
The way I see it, the D60 has a faster fps rate so the shutter will go off faster. That would help with sport photography. I just got a Nikon D40 SLR and it is great. The D40 meets my needs in action photography. I guess it just depends what you are doing and if you are like a transcript photographer.
I personally, like nikon d60 more than 400d
It has many more features and better quality of pictures than the D40 can produce.
Nikon D60 better dynamic range in the recorded images, plus newer processer.
Yes. Any lens that works with a D60 will work the same or better on a D7000.
canon xsi is much better
The SB 800 is more powerful and has more features than the SB 600
You list the 28mm & 50mm prime lenses. If these are AF lenses, they will only autofocus on the midrange and up Nikon cameras. The Entry level D40, D60, and D5000 cameras do not have autofocus motors in body, they rely upon an AF-S lens for autofocus. To replace those lenses with AF-S versions would cost more than a body with a motor. With that said, the very best non-pro Nikon camera that you can buy for less than $1000 is the Nikon D90. This camera will take advantage of the existing lenses that you have. If the D90 is out of price range, go for one of the older ones that have a motor used. These would be the D80, D70. I don't think you would be interested in the D200, D300, D700, D3, or D3x because you were initially looking at the D40 & D60. If you can spend a little more, the sweet spot right now is probably the D700 full frame camera recertified which would provide amazing image quality and could be obtained for about $2000 recertified.