I just put a 20" light bar between my tow hooks. I purchased a really cheap one with the Ram brackets included. It made a clean installation. I did it over two evenings. The first evening I did the brackets and light bar. The second, I did the wiring.
I purchased my truck used. It's a 2013, 2500. It did not come with fog lights but the previous owner, who works at a Ram dealership, had installed a factory fog light switch and flashed the truck to use the switch. I used one wire from that setup to power the relay switch which powers the light bar. The light bar draws too many amps to run it directly off of the factory fog light wiring but worked great for the relay.
Just hooked the other two leads to one of my batteries (It's a diesel) and I was good to go. I really like using the factory fog light switch because I didn't have to run any wires into the cab and the dash indicator shows when the bar is on. (You would obviously know it was on at night but during the day, I like the indicator.)