I started a Pacman mod for DooM Legacy way back in 2002, also named "Pac-DooM". I got pretty far with it, but, unfortunately, I was not able to finish it at the time, because I was not familiar with scripting.
I had the original Pacman level as E1M1, the Ms Pacman levels as levels E1M2 - E1M5, Super Pacman as E1M6, Pacman Jr as E1M7, and I was planning complete new level as E1M8 (unrealized).
It is kind of primative by today's standards, but I am willing to pick it up and dust it off if it is useful to either of us.
Incidentally, since the original Wolfenstein 3D had a Pacman level, and so DeiMWolf, the mod I am working on now, which is a recreation of Wolfenstein 3D, also has a Pacman level. This time there are voxel based ghosts.