Trailer Wiring

I just got an 05 Durango Limited with the Hemi - but no tow package. I would like to add a receiver hitch as well as wiring for a trailer. At this time I will only be pulling a small utility trailer, but would like to get a travel trailer in the near future. I think I can pick out a hitch on my own, but what should I do about the wiring for the trailer? Can I get something that can be installed by myself, or should I have a dealer do it?

By getting a simple do-it-yourself kind, am I risking damage to the electrical system? Or voiding any warranty? Looking for the best options and advice - thanks!!!