Sankey's is called SLICK SPLITS. He also has a four coin production that starts from spilting one coin into two, and then the two into four... on his DVD, Revolutionary coin magic.
Really, "splitting" is just producing coins in a way so that they APPEAR to split.
Why not try "breaking" a dollar into two half dollars. That's more what I think about when I hear "splitting". Check out Dan Watkin's version of this.
Scott.