You can start with an azimuthal map centered on your QTH from NS6T's web site here:http://ns6t.net/azimuth/azimuth.html
You can print out radiation patterns from EZNEC and other simulation programs.
Now I haven't yet figured out how to overlay them easily. I suspect you'll need to modify
the radiation pattern plot to have a clear background rather than white, then pull both
images into a graphics program to overlay them. I tried to do it in a PowerPoint presentation
and didn't get it to work in the time I had available.
One issue with this approach is that you really need to look at a 3-dimensional pattern
because different distances will have different optimum vertical angles: an azimuth
pattern taken at any one elevation angle won't really be correct for all distances.
I think you can get a data dump from EZNEC in some format that would allow you to
process it in a spread sheet, for example, that would calculate signal strength at a distance
based on the required vertical radiation pattern in the pattern, but that gets more complicated.
And, of course, standard patterns are based on flat ground. If your ground isn't flat then
something like the HF Terrain Analyzer software will give you a better idea of how the ground
affects the signal strength vs. bearing and distance.