Crazygreenbiker has a good point. Good maps require an incredible amount of work and it is fair that they be proprietory so their creators get some return for their effort. Given that contact the people who have the map closest to what you want, ask to modify their image for personal use only and promise them a copy for their use (and their copyrighting). Or just buy your own hi-rez color scanner and steal the image.
I like Photoshop for image manipulation.