Honestly, to me from a tone perspective all you need is both pickups up full, a little less treble and then adjust mids to taste. Pretty simple. Slap technique takes time and practice, and it really helps to have a teacher. There was a book called "Slap it" by Tony Oppenheim that was/is the classic instruction book—it used to come with one of those little vinyl records in the back of the book to listen to the exercises. I think you can find it on YouTube. I was never a fan of his tone but the exercises are invaluable.