After you download all those mods you may need a way to mange them all. Check out CMMOS.
http://www.combatmission.com/cmmos/cmmos.asp
Try changing things in the game that you don't like first then experiment. When I first started to play CMBO I had a hard time distinguishing the woods from scattered trees, so this was the first terrain feature I changed. I have a friend who loves tanks, so these were the first to get changed in his. I now constantly change the way my game looks (terrains, skies, buildings, etc), so it rarely looks the same each time I play