Heh.....cool mod m8!
I actually tried the same thing with rats too which was a complete laugh riot...hehehe.
I never figured out what the full limit is for spawned peds to be hired. I am pretty sure there is no limit providing that each ped has a high number set for their UniqueModelStatus line otherwise if the value for UniqueModelStatus is too low then the game will crash if you spawn more then that.