A few photos from some of the newer models in my collection from Reaper miniatures... Henchmen!
In fourth edition rules, I treat hirelings as minions and henchmen as monsters. If a character wants to hire a few men-at-arms, porters, or the like, these would be 1hp minions near the level of the PC. If a character wants to attract a henchman, the prospective follower would be two or three levels lower than the PC and have one each At Will, Encounter, Daily, and Utility power appropriate to the class of the henchman. Terms of employment may vary, but typically hirelings are paid a straight fee dependent upon the level of the hireling (normally paid half in advance) and henchmen gain a 1/2 share of treasure from an adventure they participate in. In both cases, the employer is also expected to cover the cost of room, board, and other expendables (arrows, etc) for the duration of the contract.