Afraid, are we?

[Kuruharan]

The dwarves i think it is said that they go back to the stone that they were made from.

That's what the Elves in Middle Earth thought. As far as those dwelling in Valinor, I don't think it's ever said if they had any thoughts on the matter.
The dwarves themselves said that their souls go to Mandos where they wait. After The End they will help Aule rebuild the world.
I don't remember if Tolkien ever said which is true, but I personally suspect the latter.
It seems like there was a thread floating around recently dealing with this topic, but I don't have time to find it.