Hahahahahahaha, that's like asking which brand of amp I should get!
Shocks are important, do NOT skimp and buy cheap. I'm running Old Man Emu shocks on my Jeep and I am quite fond of them, BUT certain brands are better for trucks verses Jeeps, AND certain companies cater to different environments. OME tends to be a good blend for on and off road but not "the best" for purely off road. My friend runs Pro Comp on his Chevy (37"s) and has had good results, but went with Blisten on his Jeep. SOOOOOoooo, in conclusion my advice is to join an F150 forum and get advice and opinions from F150 owners who actively off road.