Woodworker x 50 replacement parts

I would like to keep on hand some replacement parts for my X50 woodworker. I would appreciate any recommendations. Should I keep a motor for each of the X – Y – Z? I am planning on getting a Stiffy, even though I was told that my rails are thicker, but I was still like to get the rigidity

Should I get a handful of cables?

Anything else that the forum would recommend with your years of experience

Thank you