Need help finding ride height potentiometers

OK, this is going to be a wierd request but seeing as we seem to have some pretty inventive folks in various fields on here I'm putting a request out there. I'm building my own ride height sontroller for my new air ride set-up and I have been able to source everything except the ride height sensors. I can pick up a set from Accuair for $400 but would like to find a less expensive option.

For reference these are the Accuair sensors;
(4-Pack) ROT-120 Ride Height Sensors w/ Linkage & Hardware | AccuAir Suspension

What I would like to find is something similar to these, a set of linear potentiometers , or even string potentiometers that have a range of motion of 6" or so and don't cost $100 each. I have found a set of DIY string potentiometers, String Potentiometer Complete Kit (am-2674) , but they are not sealed very well and I'm worried about water, dirt, and grime getting into them.

If anyone has any ideas on where to get any of these a link of website would be much appreciated.