12mp is 12mp. The print resolution of a D3, D2x, D300, and D700 should identical since you have the exact same dpi for prints. You may have to change FL, or move in/out at the same FL, to get the same composition but print resolution is the same.
Differences in the 6mp D70 vs 10/12mp bodies only become significant in large prints or cropped images. Remember, you are printing at 200-300 dpi but on your monitor you are viewing the image at 96 ppi. I have printed 13 x 19" prints with my D70 which are very sharp. If depends on the amount of detail in the original.
A D200 vs D700 should have little difference, about 10% resolution since the long end of the sensor is 3872 pixels vs 4288 pixels. It is unlikely you would notice any difference in print resolution.
Albert J Valentino Nikonian Moderator Emeritus Vantage Point Images Mastery of Composition is the Key to Great Photography