I don't know much about western tack---few things I can think of other than the above is to consider what type of bit your horse needs and is used to AND what size bit you need. Also, don't forget a few basic first aid items such as nitrafurazone (antiseptic cream), hydrogen peroxide or betadine (for wound cleaning). I usually like having gloves (you should never handle furazone with bare hands) and gauze to apply those things. I also recommend having pillow wraps and standing wraps in case you ever need to wrap your horse for shipping or due to injury. If you do not know how to wrap, be sure to ask someone knowledgeable how to do this, as you can injure your horse's legs if you wrap improperly.