I have 2 fan operated coolers, and both are mounted to L brackets coming from under each of the headlights. I used "L" formed garage rails, the kind with the offset holes every 1/2"-1" apart.
I measured, cut, and test fitted each bracket. The passenger side is fairly easy, because you don't have the wiper fluid tank in the way.
Pull the headlights, and take a peek, you'll get an idea once you do some R&D on fabbing the mounting equipment.
Brian