Check out my Mod
I posted a Twilight mod I did for my own use. It's pretty extensive and makes the game quite a bit different. The biggest change I made was to rework all the tech trees. There's tons of other changes as well. Look at the INFO.txt file in the zip archive for more information. Also look at the README.txt file. Here's the link;
http://webpages.charter.net/chblock/Marklar.zip