I have always preferred the look of a nice browband headstall. I have had the same experience as others where a horse will shake it's head or rub on something and suddenly he is going sans bridle. To prevent that, they do make them with throatlatches like Sahara mentioned, but those are generally working headstalls. Show one-ears don't normally have a throatlatch. If I was using one though, I would much prefer the actual loop (sliding ear) to just having the slit. I may be wrong, but I would worry about the horse getting tired of having his ear pinched between the leather all the time. Not to mention that not all horses will have their ears in the same place. QHs usually have their ears set farther apart and more to the side of their head, whereas TB, some Arabs, and some gaited breeds have their ears set fairly close together on top of their head. With a sliding ear, you can move it to exactly where your horse needs it.
If you would like to see some with a throatlatch, here are some options: Hawkeye Tack & Western Wear :: Tack & Saddles :: Leather Tack :: Leather Headstalls :: Circle Y 119 Sliding One Ear Headstall With Throat Latch https://www.bluegrasshorsesupply.com...lls-108-1.html Rolled Sliding Ear Headstalls at Kyhorse.com