You can post in the HAF section:
https://www.blackhatworld.com/forums/hire-a-freelancer.76/
Make sure to include as many details (min traffic, content type, niche, etc...), you don't want to end up with some spammy platforms that won't work,
If you're looking for a method, you can use Similarweb, filter the top websites per country & check manually,
From there, you can extend the list by using tools like Semrush to find similar & competitor websites,
Also, from what I've tested, niche-specific websites tend to work better, and they do rank for foreign languages as well,
Even if the declared page language is stated differently, it will work with targetted language content (titles, keywords, etc...)