In addition, you should also try getting all versions of IL-2, especially the following.
Forgotten Battles
Ace Expansion Pack
Pacific Fighters
Believe it or not, these three versions install into one big sim. However, if you're going to wanna play online [which is fun, really], then you're gonna need to download the patches. from this link:
http://www.gamershell.com/download_7640.shtml This link will take you to the first update in which you simply need to click on which source to download it from [select the one with the lowest MB/s rate for better speed]. The following is a list of patch that you will need to install if you're just going to get the three versions of IL-2 that is listed above and if you want to play online.
Pacific Fighters v3.01m Patch
Pacific Fighters v3.02bm Patch
Pacific Fighters v3.03 Merged Full Patch
Pacific Fighters v3.04 Merged Patch
Pacific Fighters v4.01 Merged Patch
Pacific Fighters v4.03 Merged Patch
Pacific Fighters v4.04 Merged Patch
Note: These are big downloads ranging from 18MB to as much as 120MB. So you better have a good connection. Even if you're not going to play online, these updates will add more aircraft to the sim as well as more missions and improved gameplay.