You can spend the money on torsion keys but do not exceed 2" of lift in the front, this will put too much stress on the frontend parts. As for the shackles for the rear leafsprings, there's only a set of shackles on the rear of the leafsprings, the frot of the leafspring bolts to a spring perch mounted to the frame. lift shackles won't give you a harder/ rougher ride, if anything it softens the ride some because the leafspring has more movement and flex while driving.
I've been working on and building custom trucks, cars, motorcycles and semi's for over twenty years. It kinda sounds like he just got out of tech school and got a job at the dealership. Again, not trying to offend. Just helping a fellow member save money and build your truck the way you want.
The final choice is yours on how you build your truck, you asked for info and that's what we're here for is to help each other out. Let us know what you decide and how it comes out, post pictures when you can.
By the way, where are you from in Idaho, I lived out in Idaho Falls for a year back in '91, I'm originally from out in Oregon, Washington area.