Well, that makes things fairly simple, though the harness hackery may make things more complicated. What alternator to pick depends on your goals for the car, how much electrical equipment it has (and will have in the future) and how much money, time, and effort you want to put into the project. Beware of "remanufactured" alternators and other components, which are usually unreliable junk. Also beware of low-quality voltage regulators from China, which unfortunately is most of them these days. You can get a brand-new (not "remanufactured") stock alternator and an American-made genuine Chrysler regulator from Old Car Parts Northwest for reasonable money. See this post and this one regarding retrofitment of later-model, higher-performance alternators if that's an upgrade you'd like to make.
