For a basic setup (assuming the bike is plated, or able to be plated) all you really need to get are some new wheels and tires. Hell, I imagine if you really wanted to you could even just get new tires for the wheels you've got (although I don't know what size the S comes with, so that may not be entirely right).
If you really want to do a PROPER conversion, you're looking at new brakes, bracketry, wheels, tires, etc. Probably anywhere from $1000 for a basic setup all the way up to $5000 for a 'race' kit. (Note: Numbers are off the top of my head, please don't quote me)
Whatever happened to sex, drugs, and rock'n'roll? Now we just have AIDS, crack and techno.