With float I mean you could set the headshot multiplier to say x1.4,x2.3,x1.9,etc istead of x2,x3,x4,etc.
You could create an event for helmets like:
OnActivated - player - helmet "1"
OnActivated - player - setappearance "setnode" "helm"
Now the player gets a standard helmet and is protected of headshots.