Reliable Beam Break for permanent exhibit?

I am working on an exhibit that will use beam breaks to trigger different areas as users pass through the exhibit. Does anyone have an recommendations? I am guessing I would use an off the shelf beam break that trips a relay, that relay signal would feed into an ardruino to send the signal to TD.

Are there other options out of the box that supported a TD chop like DMX, OSC?

Any luck with beam breaks? Looking to do the same but with x10 of them over 200ft away. ControlByWeb makes some nice I/O devices.

I used some cheap $2 IR range finders for a project that worked fine but the range was just 15-30 cm. I am starting to play with LiDar sensors now for larger areas of detection with pretty good results. The brand TD supports, Hokuyo, work great but are pricey at $1500. I am playing with a $100 one from amazon now that looks promising. I am doing the detection in python outside of TD and just sending a zone trigger true to TD via serial.