Yes, fog lights do make a difference in foggy conditions - however - you will need to get true fog lights, forget about LEDs & HIDs, go for good old fashioned halogens, and get them from a reputable manufacturer like Hella or Bosch - be warned, there is a lot of cheap trash on the market, and you'll generally get what you pay for - Hella have a wide range of products, both budget & high end lights.
The big problem with most lights in fog is that fog is composed of millions of tiny droplets of water vapor suspended in the air, and the lights reflect off of the droplets, back into the driver's eyes - purpose designed fog lights have a sharp horizontal cut off and a wide beam angle - they need to be mounted as low down as you can practically get them, so on a lifted truck, you're looking at under the front bumper - the ideal thing for you would be the OE lights (which I believe are Bosch), if you can locate them - they're sometimes available on ebay or through Amazon.
Your fog lights will need to be wired so they come on with either just the park lamps or low beam headlamps, do not wire them to come on with the high beams, the high beams will reflect off the fog making the fog lights ineffective - the reason I say no LEDs is because the majority of LED lights on the market, even those advertised as fog lights cast a circular beam (or dozens of circular beams to be more precise) they lack the horizontal cut off required, HIDs are generally too white & too bright, my suggestion is that you go for a light with a clear (not yellow) lens, and if you feel so inclined you can try the "selective yellow" fog bulbs.
Off topic - but - where did you get your snorkel from? Is that one of the Brazilian made OGZ units?