I would think about the steps in preventing a fire first, then in puting it out. If you have an electric fuel pump, an inertia or at a minimum
oil pressure electric cut out is mandatory. Routing and type of lines and connections is next. Anyway, prevention needs to come first, then puting it out. Hand held is good to protect you, but you need to protect your value, read as cobra next. At a minimum, engine compartment, but you might want to consider trunk since that's where the bomb lives. Individual controls is also nice, but that may take too much thinking in an emergency.
What I'm saying is think through the entire process from prevention to life saving to investment saving.