None of the electronics you buy now are as good as they used to be.

My advice is to get a Pertronix kit, but keep a spare setup if you're worried about it. Anyone using an MP kit or MSD probably has a spare also. I prefer the older MSD analog 6AL boxes, but I have 5 cars using the same system...easy to swap out if needed.
I've installed 2 Pertronix kits on Mopars and both worked great.
Local parts stores rarely have anything on the shelf for our old cars anymore. So if you're worried about availability, buy extras yourself.