Onyx Boox has just released a higher resolution e-reader with the advent of the C67ML. This model has an e-Ink Carta 2 screen with a resolution of 1148×1072 with 300 PPI and has a built in front-light.
The C6 series is in its 3rd generation and this is the first Onyx Boox e-reader to employ the new Carta 2 display. This device has a Cortex-A9 dual core 1GHz processor, 512 MB of RAM, 8 GB of internal memory and a MicroSD to upgrade the storage up to 32 GB. It also has a 3.5 mm headphone jack to listen to audiobooks or music. This device runs Android 4.2, so you will be able to install your own apps.
You can purchase this e-reader from Banggood for $200 US.