I had access to, and flew an X-Air owned by our club, great little plane.
We looked around to find replacement shock absorbers and we spent more than the price of the originals in trialing some from a motorbike and some from a car neither of which worked. We needed to get replacement shock absorbers because of a really long taxi over rocky ground. It eventually wore out the rubbers in the ends of the shock absorbers that couldn't be replaced.
The ones off motorbikes are not designed for an aircraft that weighs 500 kg, they were way too soft even with the springs packed out, even with nobody in the aircraft it sat down on its tail with a shock absorbers fully compressed.
Someone else sourced a set from some sort of dune buggy but they were way too hard and you might as well have put pipes in where the shock absorbers should have gone.
Just buy the originals and problems sorted.