I haven't listened to those artists you posted but anyone with half an ear should be able to find something to love in
Will Oldham. I would start with his Palace albums and work forward to the Bonnie 'Prince' Billy material. If there's been a better artist within the genre of folk music in my lifetime then I'm yet to hear them.
Likewise,
Jason Molina isn't particularly folky, he's more blues and country but my word, what an incredible talent. His earlier albums under the name Songs:Ohia especially are some of the most empassioned lo-fi music I have ever heard. Similarly to Oldham, he has a discography that keeps giving the deeper you go.
Finally,
Jandek influenced both of the above artists and has somehow recorded even more albums than either. The Representative of Corwood Industries remains an enigma to this day, releasing as many as three new albums a year of his trademark stark, esoteric folk music. You can buy a whole ton of his records in bulk at his
website. Recommended to say the least. He's one of a kind.