[Renevatia]

Photoshop is probably your best bet for airbrushing/ matte pieces like this. Its a quite flexible program in terms of photography post processing and with enough practice and stock selection you can make something like this by editing each layer to make them seem like they fit into the same picture.
Also take into the consideration of consistent lighting and texture size of stock. Levente has a much better grasp of matte painting.
Most likely no 3d models in that picture but mixing 3d models in matte is quite common. You will have to learn how to speed paint normally (without texture or stock) first before you can do something like levente tho.