Easy:
Ace's IL-2 MAT Manager will give you historically correct markings. A lot of them are available in various forms such as weathered and changes of style corresponding to particular periods of the war. Greatly enhances the aircraft appearance especially when using the excellent skins out there. Chews up lots of disk space! Unfortunately it is not being updated anymore but all you need for the IL-2 series is covered. Interface takes a little getting used to but Ace is a graphics diva not a programming diva, so we forgive him!
DCG is Paul Lowengrins's
Dynamic
Campaign
Generator, an alternative to DGen which is shipped with the game. It is a vast improvement in a number of areas over the stock DGen. Paul is constantly updating it.
So, expanding on Brigstock above, your 'core' setup will be:
IL-2 1946 (obviously
)
IL-2 Shturmovik Stab 6.3 (shameless plug
)
DCG
IL-2 MAT Manager
Hardball's Aircraft Viewer (another excellent utility)
Now you have the 'core', just add all the other stuff such as skins, campaigns etc.