It is always difficult to give recommendations for HK factory products when dealing with clones, because there are obvious differences.
From HK, the copper colored extractor springs are for the 9mm SMGs. The silver colored extractor springs are for the .40 and 10mm SMGs and all the rifles. There is no difference in the sliver colored springs.
Some people choose to run the sliver colored extractor springs in all of their weapons, but HK specifically recommends against this in the K models. With the K, the bolt is lighter, moving faster, and the distance traveled in recoil and back to battery is less. Having more tension on the extractor can prevent the empty casing from clearing the receiver and the next cartridge being properly chambered in the proper amount of time, resulting in the extractor being caught out of position and thus bending the extractor spring back. This is a greater concern when firing the K on full auto or suppressed and worse still, when fired on full auto and suppressed.
Generally, though, if you are noticing a significant wear/damage to internal components, and failures to fire and eject, especially with clones, it most often points to the timing being off and needing to address that specifically. Sometimes that can be swapping out internal bolt group components to get the bolt gap into a better range. Other times, it requires the barrel to be pressed back in, as it was possibly not correct from the start.