Coffeepal,
I’m glad you are enjoying your Altura.
Not that it probably matters, but the sensors aren’t actually optical, they are ultrasonic…which is a much different technology and may be a factor in how you end up using the Altura.
But to answer your question, there is nothing special about the ribbon cable that connects the sensors. You could use cat 5. Whatever you use, my suggestion is to not solder directly to the headers of the sensors. Instead, cut one of the ribbon cables in two and strip the 4 wires and solder the cat 5 wires to those. That way you have a female header that you plug directly onto the sensor male header. It keeps things more modular that way and easier to troubleshoot or replace things.
One factor you need to be aware of is that the Altura has no driver for the sensor signals, so there is a finite limit of how long the cables can be. The distance depends on the capacitance and resistance of the type of cable you are using and the drive capability of the microcontroller and sensor hardware. If you want to make it much longer than what it currently is, you’ll just need to experiment with what works for you. I imagine that a couple of feet of cat 5 will probably be fine, and cat 6 would even be better.
Good luck.
-Brach