yano.
looks like you should consider searching for scotch n soda as a basisi for this trick but think more along the lines of a scotch n scotch.
it is definatly in bobo's modern con magic book, also consider the dvd shellraiser.
regarding mercury ring, by sankey, I'm asuming thats the one your refering to then there isnt a decent cheeper version though some have done it with a jardin ellis ring its not the same and dosn't have the same impact.