Try freeports or freelancer station, they usually have bribes for factions that are active around there.
Judging by the files, a male Gateway NPC and the bartender on Freeport 1 in Omega 3 should have bribes for IMG.
Additionally, Freeport 6 in Tau-29 also features IMG bribes by the bartender, a female bounty hunter and an IMG (although that one won't speak with you if your reputation is bad).
And please open a new thread next time instead of digging up a thread from 2012.