Thanks for the suggestion komaokc I actually don't know own UE4 yet but I'm planing on getting it soon I have played around with UDK for a long time so I'm really interested in getting UE4. But thanks for the suggestion
I think this scene is probably a bit too big for marmoset. You'd get better results in UE4. You can create some really nice landscapes with world machine. And you can make some more complex materials.