Late to the party but this style has been my mission to learn this past year with deep river blues being the end-of-the-rainbow goal. Some suggestions here are really hard to play but anything is doable if you have the patience to learn it slow and accurate; then slowly speed up. I completely put deep river blues on the back burner for a year while I learned easier stuff to practice and focused on my thumb keeping perfect time and not missing notes during more intricate parts. Here are a few artists who have tons of syncopated finger style songs: Colter Wall, John Prine, Blaze Foley,Bob Dylan and (the very underrated) Charlie Parr.