You can buy Nintendo WiiTM Remote units (a.k.a. "wiimotes") at nearly any electronics, gaming, or department store. (I found EB Games here in Sydney at Westfield, Bondi Junction, very helpful. They also advised me well to get a 2-Wiimote charging unit with rechargeable battery pairs in a small cartridge cleverly designed to fit into the Wiimote.)

You don't need the Wii console, and you don't need the "nunchuk" controller extension.
You don't need the Wii position sensor bar; we'll only be working with the triaxial accelerometer signals from each Wiimote.
DO read the safety instructions from Nintendo and DO always wear the strap for your Wiimote.