SoGE is a Star Wars Total Conversion for SoaSE: Rebellion with it's roots in the Homeworld 2 mod Star Wars: Warlords which features the two primarily sides of the Galactic Civil War, the Clone Wars, and the Yuuzhan Vong War. The current public version works for Sins of a Solar Empire: Rebellion 1.86 and, with or without, all DLC. Rated #6 players choice in MOTY 2014. An editors choice in MOTY 2015.
This wasn't easy to pull off, and contrary to what these pictures show, there still is a lot of work to be done. Lots. No ability/buff files have been converted over, but I have the planets, ships (no abilities for these two), particles, and sound/music in.
If it weren't for research being totally broken (read: virtually non-existent) and all the militias being vanilla Rebellion units, you could play an Empire vs. Empire game.