So, Hexstrike says the following:
When you gain this feat, choose one hex that you can use to affect no more than one opponent. If you make a successful unarmed strike against an opponent, in addition to dealing your unarmed strike damage, you can use a swift action to deliver the effects of the chosen hex to that opponent. Doing so does not provoke attacks of opportunity.
So my question is this, can you use hexstrike with weapons that modify your unarmed strike such as gauntlet, cestus, brass knuckles, emir piercer, etc. or can you only use it with a non weapon unarmed strike?
According to the wording of a gauntlet it modifies the damage of Unarmed Strike, so you're still using an unarmed strike ... As far as I can see that means you can use Hexstrike with a Gauntlet.
Ok cool, that's how I read it as well.
If the hex is an SLA or SU hex, then you can also use any Conductive weapon.
/cevah
The wording of cestus et al. is one of the biggest sources of uncertainty in all of Pathfinder. There are posts by Sean K Reynolds back when he was an important member of paizo saying that those weapons shouldn't reference unarmed strikes at all; but nothing official.
Just use handwraps, you'll save money on aspirin.