what i can tell you is that while somewhat the same the android and linux builds come from 2 developers. pine64 the company develops a build for all boards in android and linux. and then ayufan , a developer who is responsible for all of his builds as well as a good portion of the pine64 code in android & linux.
if i were attempting to do what you are i would forget about the emmc thing at the start as that seems to actually be the smallest problem and by starting with just the sd card you can more quickly determine the fitness of any particular build as far as getting the lcd up and functional and reduce wear and tear on loading and then loading again various builds to the emmc.
also, as for android i would suggest you start with the 7.1 early builds as they are the most stable and bug free at this point even though they are not the most recent. so, start the search for android 7.1 from ayufan & a pine64 android 7.1 community build.
ayufan 7.1 android builds here,
https://github.com/ayufan-pine64/android-7.1/releases
even among the 7.1 there are earlier builds that tend to be more stable, but often depends on your interests, scroll down for earlier builds marked 65 / 64 / etc
then pine64 android 7.1 community builds,
these are the pine64lts/sopine
http://wiki.pine64.org/index.php/SOPINE_...re_Release
you need the lts/sopine because of the memory each of those boards uses. they usually only have 1 or 2 builds. you will also have to learn about how to set up emmc, there are a couple of ways.
that should be enough to get you started in pretty much right direction. i'll end for now by saying we all understand the frustration , many of us have been through it multiple times. but, if you just relax and accept that you will have some work to get it set up and it's not all a piece of cake but that these things do work rather well when it all gets ironed out the you will have a better experience with it.
