lazruck will socket his helm for you (one of the first quests in act V). Your mercs stats are independent of the lvl you hire him.. there is no bonus to hireing a merc early as to late; however an act 3 merc from normal will have better stats than and act 3 merc from hell so you should always hire your merc in normal (obvious exception, NM - a2 mercs for a specific aura) Never hire anyone in hell. If for some reason, you love your mercs great name perhaps, you want to keep the merc, play private games alone and let him or summoned minions get the kills. Mercs only get a small percentage of experience for monsters you kill. (conversley monsters he kills you both get full exp).