Install IL-2, patch it up to 4.13RC, and then us the Full Mission Builder from the main menu to make yourself some missions!
The best way to do what you are describing (which is the only way I play) is to make your mission, and then set bases and start your server as a dogfight server... I know this doesn't sound right but it's way better!
If you start a coop server everyone is locked into a certain aircraft, when they die they stay dead and have to wait for everyone else to finish the mission, and then you have to start the mission all over again.
When you do a dogfight server, you can set the bases to have certain aircraft and loadouts available to your human players, and when one of them dies they can choose another plane and take off again to continue the mission. You can set it so there are a limited or unlimited amount of aircraft available, but basically the mission keeps going as long as you want. Saves alot of time and you can still be on the same side, it will give you the option to choose sides when you join the server.
You can do a simple mission, or you can set repeating waves of AI fighters or bombers, set trains and ground targets, ships, etc... And just keep playing until they are all dead. Great fun!
If you aren't sure how to use the FMB (it's pretty complicated) here is a good place to start.
http://www.mission4today.com/index.p...ge_Base&cat=95
You shouldn't need a dedicated server, just set up your port forwarding, host a game and let everyone join and you should be good as long as you have decent upload speed with your internet connection.