I've been down this road with my Cuda, so I'll make a few hopefully helpful comments: make sure your charging system and wiring is up to snuff. I highly doubt that the typical 79A Mopar alternator will cut it. The stock 12 ga charging wire will definitely not be sufficient, so start thinking about a higher output alternator and a much bigger charging wire. You also need to decide on your fan control system. Are you going to simply use a switch to turn the fan(s) on/off? Probably not the best idea for any sort of city driving, so think about what fan controller you want. There are many different options available.
Just wanted to mention these things, because they are often overlooked, but they are equally as important as choosing the fan(s) themselves. I can go into more detail about what I have done if you want.
Hope this helps.