Agreed on the fact that bitless can be harsh in the wrong hands as well, and the double jointed eggbutt snaffle would be my bit of choice if I were to use one.
Just as with bits there are many options for bitless riding, and it depends on what the horse likes. You can clip reins onto a halter, or spend up to hundreds of dollars on a Dr. Cooks. Most are fine and will work well given the horse is properly trained and the rider is confident and compotent, the only style that I will suggest you stay away from would be a mechanical hackamore, as they can be particularyl harsh, especially if placed too low on the nose or used with a chain curb strap.
As Charis mentioned quick release is very important, because horses learn from the release of pressure, and not the pressure itself.