P.P.S. Just for gits & shiggles, I renamed my project the Atari VCS 1600 Build. The Atari VCS had several versions, each with different faces. What determined the 400 or 800 designation was the amount of RAM. The 400 shipped with 4GB DDR4 while the Backers Edition sold with 8GB DDR4. It is possible to upgrade to 32GB, but the GPU is limited to 4GB, leaving 28GB on the table for the OS and apps. At today's prices, I think I will hold at 16GB - $300+ for 32GB (2x16GB) sticks my ass!
Interesting discussion about RAM upgrades on AtariAge.