Yes, a game with monsters would be cool. I wanted to make a very similar game to this, but just had too many games going on at that moment. I am curious, why do you want to have so many AIs to be around. Just the Monsters would be better (IMHO, of course). Also why would you want to play in a huge (255) galaxy?
Anyway, all the monster stuff can be copied and made to work with the standard game. IIRC someone said, they wanted to do it, but I don't remember who or if it was ever done. One thing to keep in mind, though. Some of the techs in Devnull Mod are pretty helpful against the monsters. The external missiles can overwhelm the monster PD and keep those buggers of your back for a while (until the next generation arrives
).
With 5000pts and many starting planets, I assume the monsters will be very tough. Sounds like fun.
Rollo