71 dart electronic ignition conversion...
A Pertronix is a good basic conversion; for a relatively stock motor it'll work as well as anything else out there. And they're quite easy to install.
One trick you can do if you want a step up but don't want a huge orange or red box taking up real estate under the hood is to take a stock Mopar electric distributor and wire it up to a 4 pin GM HEI module. The HEI is pretty powerful, a bit more easily hid, and it lets you do away with the ballast resistor. I know it's not Mopar, but at least you can get HEI modules that were never built by GM either. :)