I draw your attention to this map, from the project rho star-mapping site. It is a subset of this map, showing only stars similar enough to our own to be good candidates for Earth-like planets. Both push out to 50ly. I think this is a good start point. We want to emphasize the habitable systems and allow the small red dwarfs be significant only for compelling strategic reasons -- that will punch out the limits of the map, since as we go out to 50ly there are probably a lot of dim stars missed.
I also need to establish a frontier zone so that "known space" has an "outside" that is within the scope of the data we have. And most of all, I have to find a way to present the data that works and is easy to visualize and work with.