Why not run a yotaphone? E-ink on one side...

Yes, and LCD on the other. I tried to get my Nook to run TopHat and have had zero luck. It is not possible withouot taking it apart and doing some soldering.Even then you have to have a serial output GPS. Newer USB output GPS will not work. I was lucky enough to test fly a Yodaphone (not sure about the spelling) and it worked well. However last time I searched for them online they were not sold in the USA. Probably because
they are made in Russia... might include spyware at no extra charge :-)