dear sir ,
i am a professional inventor , i make cad designs , patents , prototypes and production steps with cost consideration
i found what you are asking for is interesting to me , as you know sir to have an HD you need a strong light source , which mean more power than normal , also a special HD inner LCD and liens
so if you need an HD it will not be low power , it will be portable , it will totally support android , and other OS , it will also has it's own mini OS to provide run media with sd cards and flash memory
so that what you will get sir , if you want me make a sample we will speak about it and how to send from here to you
good luck