Be aware that non-lethal options for self defense are often completely ineffective and leave the defender with a false sense of security.
The CED, commonly called a TASER, is only effective when two wires make body contact to center mass within a certain distance. Heavy clothing will defeat them. If the assailant makes sudden turning moves, the fragile wires will disengage. IF the shot is perfect (you only get one, two with some models), the charge only incapacitates the assailant for the 5-6 seconds the charge is active. There is no stun effect. Once the charge is depleted the assailant regains full muscle control and will probably be super-pissed off.
Police are trained to used TASERS to incapacitate a non-firearm wielding offender just long enough for a second officer to get in and cuff them And it's a very short window.
OC, or pepper, spray, is often ineffective against angry or substance affected people. The effects of the spray often won't kick in until after several minutes. OC spray requires you be within 2-3 yards of the assailant and get the stream of spray onto the assailant's face. Bug sprays, if they get into they eyes, can blur the vision, or force the assailant to close their eyes for several seconds. It won't incapacitate them.
If you're going up against an armed gunman, particularly one that has already demonstrated he will shoot and take victims, your best alternative is to continue shooting the assailant in center mass until they stop doing what they are doing. One shot is often, but not always sufficient, to achieve that objective.
No, you shoot two to center mass, then switch to the head. Every body has body armor now.