Love stock trailers! My next one is going to be a modified stock.
If you don't have something like one of these under or on your truck's dash, you don't have a brake controller. I'd never haul without one. Brake Controller | etrailer.com
Walmart sells a pretty decent one, and as has already been stated, if your truck is equipped with a tow package you'll have the wiring in place ready for installation.
I bought the Walmart one for my previous truck and it worked fine. When that truck got totaled last year, I bought a more heavy duty one for the new truck. More power never hurts!