How exactly do you achieve a good headset? What am I to be doing with my hands ect. and how exactly do I want his head and neck to look?
This isn't something you can learn by reading or in a post on the forum here. From the sound of it you have no experience either riding or driving a horse and I would highly recommend for your and your horses comfort and safety that you get some lessons on a well trained horse with a good teacher.
I do have a bitting rig although I don't use it as such. It does have many uses other than creating a head set which will do your horse no good anyway. I have one for Minis and one for ponies as they are far more adjustable to fit many sizes of horses than a harness saddle is and I get all sizes of Minis and ponies in for training. I don't use the harness until I am at the point of hitching up and I can ground drive and train them to yield with the bitting rig. I don't believe in the use of side reins or martingales or checks and won't put one on a horse until the end of its training and only then if I know it is to be used in the breed show ring. I don't recommend any beginner to use any of these appliances on their horses as they don't know the correct and proper use of them and will do more harm than good.