Any action or inaction in a position of power will always grant you enemies
I have the horrible sensation that after you have found one youll make dynamite and begin to suicide bombing at NCR....PD: Thief arent populars here, and i love Aladdin movie
Most major NPC factions have one, I'd gather, and so do the Gun Runners. Probably your best bet reputation-wise is to do the delivery job for the Gun Runners until they'll let you use theirs.
there one is in military base 4th level.