Create your meshes + textures + skeletal meshes in 3ds -> export and import them -> create the materials -> create the level with the meshes. 
You are much more flexible when you create the level in the UE4
Create your meshes + textures + skeletal meshes in 3ds -> export and import them -> create the materials -> create the level with the meshes.
You are much more flexible when you create the level in the UE4