Recommendations for alternative fashion project

I want to experiment more with my aestethics, going into a mix of corp goth, cyberpunk, and techwear. A lot of belts, buckles, and chain accessories. What I don't want is to buy from Amazon or other companies that mess up the planet and their employees with their production.

Because of that, I would like to approach two possibilities:

1) I am looking for sellers who sell sustainable fashion around the above-mentioned styles and

2) edit basic pieces myself and for that find sustainable sellers of the necessary raw materials (belts, metal chains/buckles/...).

I am happy about every piece of advice and recommendation regarding that project. (^w^)