All good suggestions. I also agree that this horse must already be responsive to leg aids, so that's a plus for you.
It pains me to see that most bridles these days are sold with flash nosebands. This is to keep the horse from opening his mouth, which is his way of giving feedback, that he is not understanding, or is in pain. The best new infomation today on teaching a horse to accept the bit naturally, without strapping their mouths shut, is Linda Parelli's 'The Game of Contact' DVD. Walter Zetl, says, she has explained the unexplainable, and I agree. This is a must have DVD for experts as well, to show you how to teach students via simulations on what contact is, and how to get the horse to also understand it. For more info go to http://www.parellinaturalhorsetraining.com