Can you enlighten me as to the current state of e-ink and e-paper products?
I am mainly looking at printers who let you print out to an e-paper.
E-ink and e-paper isn't really ink or paper. It's a display, that requires power (at least temporarily) and electronics to control it, like any LCD.
It's called "e-ink" and "e-paper" because, like ink on paper, whatever you program the display to show will stay there without power, and it will give you similar readability in normal lighting situations as ink on paper (if you had a thick pen on gray paper, at least).
As such, you can't "print out to an e-paper." The closest parallel would be "send to Kindle," that transmits a document over wi-fi or USB and has a program on the Kindle display it on the screen.
E-paper (bistable displays) development kits are generally available now at varying sizes from both manufacturers (like E-Ink) and distributors (like SparkFun or Adafruit). You can also readily disassemble many older Kindle and other e-readers and write your own programs to prototype things on their displays.
If you mean printable circuits, where something resembling an inkjet printer squirts out conductive metallic ink on a non-conductive sheet to make a circuit "board," I don't really know the state of that.