Dude… you have got to check out HBGs new Global War series. I am just finding out a lot about this myself. The Global War 1936-1945 game is supposed to be released next month.
This gets into almost all the stuff you just mentioned. The games are going to start in 1850 and move all the way up through 2025. The board is huge (bigger than G40) and full of more intricate elements including the possibility for the CSA. I think your game may already be here.