The Fuse Alpha Shin Whip Pads look good, but according to the charts, my size would be 2XL, which American shin guard websites do not seem to have in stock. 2XL also sounded like it might be too big for me, so I wanted to find a bike shop where I could try them on, but that appears not to be possible- a bike shop owner told me that knee and shin pads are now something that bike shops leave to the Internet.
So I’ve been using $10 soccer shin guards that have ankle protection. It seems to me that shin and calf protection for my sort of unicycling (introductory flatland and street) is mostly for stopping light impacts from pedal spikes, rather than blunt force trauma from trees and boulders, so just a hard shell should be enough, and padding isn’t really needed, especially for the calves. Inspired by this thread, I sewed some wedges of plastic floor mat into canvas, and got a better result than expected: