For protection i suggest the 19. For competition go with the "C".
Why? Speaking of protection, if you are getting out of your car on an empty parking lot at night, then someone at sudden coming to you intending to rob with a knife. You can easily pull out your gun from hip holster and shoot him with it without gas bursting out to your face. When aiming also, you wont get sight blinded as the gas bursting from the ported barrles will be visible at night.
Just my 2c.