I think at this point only Vertical licenses those kind of manga. There is Drawn & Quarterly and Fantagraphics, but I don't know how much committed they are to manga these days. I generally just periodically check out what they have on twitter or whenever ANN covers their press releases.
As for suggestions there is Satoshi Kon manga Tropic of The Sea. Helter Skelter and Pink by Kyoko Okazaki. Sunny from Taiyo Matsumoto. Nijigahara Holograph from Asano and A Distant Neighborhood by Jiro Taniguchi. Town of Evening Calm, Country of Cherry Blossoms by Fumiyo Kouno. And I guess everything by Tezuka (Buddha, Phoenix, Apollo's Song) if you haven't already read him.