I agree with Flying B. You never absolutely need a chain, not even with stallions. Its true that a chain can be used responsibly, but by no means is it necessary if a person takes the time to ensure that the horse is respectful and trained on the ground to begin with. It doesn't matter how hyper the horse is. Take it in an enclosed area and work it on the ground. Teach it manners and train it to respect you. All it takes is effort on your part. If the horse trusts and respects you and you've spent sufficient time correctly working with it, then you will have control of the horse.
I think that maybe you need to work on your own confidence more. I'm sure you're very capable of working with your young horses so that you won't need a chain. I'm sure you also use them responsibly, but the fact that you think you NEED them points at your fear of being out of control. Believe in yourself! Plus, if you lost your temper or got frightened and started jerking, its easy to upset the horse and deliver unecessarily harsh punishment. You may very well do it without intending, and the horse can quickly get head shy, or become unruly and dangerous because its upset with being unfairly handled. I think you are more likely to end up with an "out of control" horse by relying on chains and not ensuring that you can control your horse with the least force/contraptions possible, which I believe is the true mark of skill, harmony, respect and control in a relationship with your horse. Have faith in your abilities. I'm fully willing to believe you have what it takes if you just give it a try.