Is this a tub only? If so you will most likley need to replace the faucet with one that has a hand held shower, or you will need to add a diverter valve with a hand held shower.
You can also look on the websites of popular companies such as Kohler and Moen to get ideas, then talk to your plumber to find out whether your existing tub valve will work with the fixture you choose. "Plumbrite" is correct, though, I've installed the hand-helds on my two tubs and in both cases I needed to have one of my plumbers change out the valve/diverter first. It was well worth it though!
Checkout faucet.com; http://www.faucet.com/index.cfm?term=tub%20s...
Tim