City,
Believe it or not, there is a lot going on here. I will try to give some guidance here, but; ultimately, you will make the final decisions as to what you end up doing.
Years ago, (about 42 or so) when I was fresh out of the service, I used my GI Bill to cover my expense at Red Tomlinsons School of Horseshoeing. My first chaps came from the school, since then I have had/made many different types out of many different typesof materials, and finally 42 years later, I have come up with a pattern and style that I really like and seems to be well regarded by the professional shoers around here, they have no problem paying $100 for a pair. The way I got to this point is by looking at what a lot of guys at the track were using and asking what they liked/disliked about the ones that they were using. Bottom line, what I have come up with (no big surprise) is something that wears well, fits comfortably, and equally important can be gotten out of at the drop of a hat (in case of emergencies, and there will be some!) For material, I use 7/8oz pearl grey sides from Weaver. I put a belt on them that goes around and buckles at one side. The belt also has some elastic at the buckle, (about 4" of 1 1/2" heavy duty elastic that I use for english cinches) so that it "gives" when the farrier bends over and does not bind. Also on the opposite side of the chaps from the buckle side, I attach the belt strap with 2 snaps and a tang sticking out so that in an emergency he can just give it a quick swipe with his hand and be out of them in an instant. Also, I put a leg strap on each leg that pulls around and snaps to the outer side of the chap and alows for that same quick hand swipe for freedom. Finally, I put a pocket on each leg that will allow for the insertion of a rasp/hoof knife, nippers and so on. On those pockets, I leave a hole at the bottom just large enough to allow hoof shavings to pass though rather than collecting and subsequently having to be emptied. If requested I also add magnets for nails, but; not my personal preference. I will take a pic of a set I have down in the barn when I get down there today and post for you.
Hope this helps.
Bob