While the advantages of being lower are apparent in terms of center of gravity, lowering your vehicle with out taking into consideration other suspension components, alignment, driving style, etc... You can end up doing more harm then good
Excessive tie rod angles lead to bump steer, not enough travel between can cause bottoming out, and natural instinct being to just stiffen everything up to compinsate. This the makes everything worse by not allowing your suspension to do its job... The list goes on. Your vehicle should end up being lower then stock, as a by product of perpetuating its ability to corner to flatter, smoother, and safer.
If your only goal is super mega hela flush, go find a Mini truck forum, notch your frame, tub your bed and drive around on the frame rails...:rolleyez: