We all know how hard it is to find 20 y.o. decent brake parts, even for rebuilding.... I got a 2000 Banshee for some money a guy owed me and I kept a few parts. So, when I got the 86 200X with no brakes at all, I installed the Banshee brakes on it. They stop and work great and can be found fairly cheap and these quads are just a few years old.
The caliper was simply one offset bracket with an 8mm tapped hole and an 8mm clearance hole - done. The master cylinder got a custom 1/4 inch aluminum bracket (bolt missing in photo) and it bolted right up. I think I had to swivel the hose barb connection and then used the stock Honda res.