when you're talking about a suit of armor, it's called a bevor. when you're talking about the punisher's high collar it's just part of bomb disposal suit or higher caliber bullet proof vest (still might be called a bevor, i have no idea).
gorget's are designed to protect the neck area/collarbone area but are usually fairly simple. bevor's either attach to a gorget or are made as part of a gorget but are specifically the part of the armor that protects the neck/lower jaw.
this is a gorget
this is a gorget with a bevor