I’d use one pair for your 1-wire setup running with the other conductor connected to ground on the sender side only.
Run another pair both 5V, and another pair both GND.
Stranded is always better for power, due to skin effect, but these sensors don’t need a lot of power, so go with cheap cat-5 or cat-6. Now for a newb, stranded might be better wrt soldering if you don’t plan on having RG-45 terminators.
You want a 120 ohm for each sensor. It is a transmission line, any deviation off the main trunk is a stub and thus you are trying to reduce the impedance mismatch at the stub with that resistor.
At each stub, I would also put a pull up to 5V on your 1 wire. Power is there, you might as well. If you have a bunch, make it 10K each or 47K each. The object is to keep the signal from getting into the unknown region.
If you do find some shielded ethernet cable, again, just connect the shield on one side. Attaching both sides makes what is called a ground loop and if there is any voltage difference between the grounds, you can make the noise problem worst, not better.
Also, don’t worry about it, dealing with electical and RF noise is more of an art than a science. Takes many years to get the hang of it, and even if you are well versed in the science, and many years of experience, it is still fun to hear the greenhorns exclaim, “But it should just work!!!”.