Reining at the beginner level is pretty informal as far as attire and equipment is concerned. A western saddle, and western riding attire is the general standard. You can have "bling" on your horse and equipment, and it may add to your overall appearance, but you are not judged on it specifically. One must pay a bit of attention to the bit you choose to use. Riders are asked to remove their bridle at the end of the run to have their bit checked. If you are riding in aWCRA modified class, you may use any legal bit, and ride 2 handed. These classes are designed for beginner riders and/or horses, hence the more open ended policy around bits. For more specific rules around this check the WCRA website. (http://www.wcra.info) Most people that are reining have their horse fitted with sliding plates. This allows for the spectacular "slides" which are the signature maneuvers of the reining horse. They are not required, and in fact not necessary until your horse is able to get under himself when asked to "Whoa". Working with a trainer is the best way to teach your horse this skill, and your trainer is best to advise you as to when it would be a good idea to get sliders put on your horse. Once your horse has sliders on, you must consider where he is going to be housed! Sliders typically extend beyond the back of the back feet, and they are slippery! If the horse is on uneven terrain, or turned out in a large field or pasture, it is potentially dangerous for him, and your sliders will not last very long! Another issue in our area is finding a farrier with the knowledge and skill to put sliders on correctly. The nail heads must be rasped off (or you have a rough surface) and often reiners like to "roll the toe", which the farrier must know how to do properly. Ron Burfoot has been our farrier for years, and has put sliders on our horse for us. He is hard to get, but maybe if we had him booked for a day to come to town and do a bunch of horses, he might accommodate us! Especially if we could convince him to join our club!!
I'm certainly not an expert on any of this, so please feel free to add comments to this post in regards to anything I may have said here that is incorrect, or that you would like comment further on!