Quest - Poor People Are Poor Customers
Quest Pickup - Kingpin Mansion (F8) (Kingpin)
Quest Location - San Mona (D8)
Quest Finish Point - Kingpin Mansion (F8)
Simple quest, take the down of San Mona, quest is Solved, you still need to talk to Iggy, then the quest will be complete, and then you can speak to Iggy and get him to join you.