Answering whether wool or latex is best is difficult, as this is a very individual decision, and we recommend that you try out both to see what suits you best.
The advantages of latex are that it retains its shape over a longer period and does not require re-stuffing or similar maintenance. Saddles with latex panels can be used on multiple horses with the help of saddle pads that offer correction.
The advantages of wool are that the panels can be custom-fitted to a single horse with great precision and can be adjusted as needed.
The disadvantages of latex are that it cannot be adjusted or re-stuffed by a saddler, as it comes in a standard shape.
The disadvantages of wool stuffing are that it compresses over time and loses its elasticity and spring. Wool stuffing requires re-stuffing and regular checks. How often this is needed depends on usage.