If you want custom steel bike frames, my suggestion is to check your local bike builders. My personal experience is that you don't need to go far for reputable steel frame builders. It'll save you a lot of trouble & additional expenses like international shipping & custom duties/taxes.
But if you really want to pursue that, you can check out Ave Maldea, he's from the Philippines (where I'm from). Very well known & established here, and had done several frames for folks from different countries. He works with hi-tensile & chromoly steel, I believed he had worked with stainless steel as well. Practically a legend to Filipino cyclists. The bad news is he's swamped, like a 2-3 months turnover. And the COVID situation doesn't make it easier. I believe he can do a hi-tensile steel frame for under US$200. Not sure if that includes paint jobs though.
