Unfortunately I don't remember what channel that was. But they did a lot of comparisons to show why. You can pretty much get that idea just looking out a jet window, since the Earth already looks pretty smooth even at that close range.
It'd make a very cool art project, though.
I wonder if it could be 3D printed with reasonable precision to suit your needs. I'd look at shapeways, and if you can't find it maybe somebody can 3D model it for you first.