Worn that tee-shirt. Also, done a bit of research into this at work for a very different environment. You're going to hate cap/pcap systems - if you have any foreign grease or liquids on your hands. Bezel-based IR is pretty reliable, but you miss the haptic feedback and suffer false activations (some systems integrate resistive, or SAW sensors to verify an actual screen-press), SAW is not particularly suited to high vibration environments... good old fashioned resistive can be one of the more robust solutions - not the most elegant but for simple podge-type applications it can work well.

I'm supposed to be developing a touch-screen for my SX2.7 but starting to doubt the sensibility of touch for a mill. Previously used a resistive PoS monitor which was pretty robust, but as Jazz says - ends up full of grime.