Leaf spring left kits usually have more leaves stacked and/or more of a bow in the spring. They are almost always significantly stiffer than the stock springs.
Shackles just lift the body up and away from the spring to give you more ride height and possibly more wheel clearance.
Which you go with depends on what you're trying to accomplish with the lift.
The biting point of a brake pedal can vary from one model vehicle to another. Car and Driver magazine often comments on that specific location when performing vehicle reviews. Some models have what they consider excessive travel before engaging, while others have a short, immediate actuation.
If your brakes are solid once the actuation point is reached, you ...