Lots of good options. In the rear, the single best thing you can do is a new leaf pack. But that's expensive and you'll loss your weight carrying capacity, unless you add air bags (the best possible combination for a open bed truck that still works for a living). Second to that, is a set of mini packs which will allow you to have more that 1 inch of rear travel (unloaded).
Up front, Thuren springs are the plushes (but designed for his shock valving) followed by Carli's. Not sure where Lorenz's "plush" springs fall in spring rate. Stay away from KORE stuff, way too stiff, I've used their stuff and it's in the garage now. Any of these will give you about 3" front, 1" rear lift necessitating larger tires.
If you don't mosh it off road, a 5100 series Bilstien shock from the above vendors will do very well. Remember, you get what you pay for and the bigger the shock, the better the ride.
If you want to keep stock springs, and tires, get some Bilstiens and some mini- packs and don't use all of the stock rear axle spacers.
Oh, BTW, you'll have to call or email Don Thuren as his web page is woefully behind is actual offerings.