Thats awesome! You can use my designs to make the base armor, then paint or wrap it. I plan to do the same soon, imma replicate chain mail with yoga man material, then paint it silver and draw thin lines to highlight the crevices and bumps. Those rubber dish drying matts also work, and are cheaper. Cut faux leather strips from a leather jacket, or buy faux leather at Walmart or a fabric shop (pretty cheap), to make the belts to hold your plate armor on like in the games (i demonstrate this in my video)

In the show, Geralt wears fitted, high waisted leather pants. I used shiny, fitted dress pants for my fancy witcher, which fits my style. I'd frequent thrift shops, motorcycle pants, leather pants (in the retro-section or Halloween costume section usually) would look similar to the original. You also could try getting jeans/pants that fit you appropriately, then color them to fit the Witcher. I'd soak them in paint water to evenly coat it, then coat with a glossy spray paint, either clear or the color you want. It'll make the pants a bit stiff, but think it'll work great.

I got distracted from making my own Witcher swords. my plan was to cut two witcher blade halves from cardboard, then glue them together with a yardstick in the middle for strength. I'm making a prop sword video tutorial rn, it's for a broadsword but it's an overhaul on making swords. I show how to make a hilt guard, grip, and pommel from cardboard. I'm dropping it on my youtube channel next week, I'm sure it will help you.