We carry a KZ-499A shock which is used on the rear forks of MAD scooters. Here is the link to it:
We do not currently carry a front fork shock for MAD scooters such as the KZ-590, however, we are looking for them and will carry them as soon as we can find them.
We just found a supplier for the KZ-590 front fork shock. Does your front fork shock absorber have a LBS/IN specification on it?
We can get KZ-590A shocks with the 450 lbs/in spring rating. Here is the link to it.
We were only able to find them in black. We were not able to find them with the silver finish like in the photo you attached.
I just checked and the rear shocks are only available in silver.