What Bill Hanlon said. Do that.
I certainly would really like for Pertronix, or some other manufacturer to create a points replacement product which is idiotproof. When the Pertronix unit does work, it is as good as a fresh set of properly adjusted points. Not better, but just as good. They do not suffer from the natural wear and unavoidable erosion of any points contacts (because they don't have any), and there is no issue with the difficulty of finding reliable condensers these days.
What Pertronix has a history of, is reliability issues for a number of shortfalls. Number one is that they self destruct if the ignition is left on without the engine running. This will fry the module and melt the coil. I do not know if the Pertronix III has resolved this issue. Number two is, that if your unit fails on the road, you won't likely be able to find a FLAPS nearby who carries one for you to install.
Carrying a set of points in the glove box seems like any easy back up plan, but it is not. You will need all of the original wires to go from the coil to the distributor, a good condenser, the special insulator for the distributor wire, the ballast resistor to keep your points from frying, and the wires associated with the ballast resistor, and a coil designed for points.
