You don't need a projector. You can use it with ANY LCD screen.
Also, you can get IR LED pens at this site:
http://www.maxmax.com/aXRayIRLights.htm
I'm not sure how good they are for it, though.
The Wiimote isn't tracking the reflected light. It tracks the LED itself (his LED isn't bright enough to create a viable reflection). The pens I linked, I believe, are more powerful, so they're work differently but I'm sure there's still an easy enough way to make it work.
SW-5120-1900-6153