Gesture sensing TV coffee table - what sensors would you use?
Perhaps if you drop the monitor an inch or 2 away from the glass you can use a Frustrated Total Internal Reflection (FTIR) IR scheme.  But at that shallow angle it will be tricky and may require several cameras around the edges. 



added later...  

Should mention the parallax problem given there is a gap of an inch or more between the monitor and the touch screen.  FTIR is better when you project the image onto the touch screen.

If you don't mind lower resolution, I believe the micro dose dispenser soda machines use a capacitive touch wire mess embedded in the transparent plastic front panel.  Although micro dose dispensers appear to only need to emulate about 100 to 200 buttons.  Not enough to control a mouse with any accuracy.  But enough to control a GUI designed with such constraints.

Loose high resolution capacitive touch screens can be bought with out a monitor.  However they tend to be much smaller then 32 inches.