The revised Wilson2 has a rack actuated z probe. There are new videos for that assembly. Check out this youtube video. He starts puting the rack together about 13 and a half minutes into the video.
On the Proximity sensor: If you have had good results with it, then go for it. I personally have switched to a BlTouch clone (3DTouch) that works really well. But with any sensor you add, you need to find a way to mount it to your printer. (and get it close to your nozzle.)
When you use your own sensor, then you can use the latest marlin firmware. It takes Marty a while to add in his rack control code and release it to the community.
Just a note. If you do use the rack, you will loose 5mm or more of print area due to the space required to raise and lower the rack. Also you will need to use Marty’s firmware to make it work.