I purchased my Android Head Unit from Avin, here is the link:
https://avinusa.com/12-30-multimedia...2009-2016.html
They were pretty easy to work with and they provide some software updates on their website as well, along with a support section. These units don't come with any instructions or very little instructions, but they are relatively simple to install.
I bought an older version of the unit I linked above, but it looks about the same. Good Luck!