In stock where?
I had to buy my custom LH cheek piece off ebay from the UK. I haven’t found anyone in the US that sells them.
FX used to make/sell a left handed version of the Wildcat MKI, but they likely didn’t sell enough to continue production. You can sometimes find used ones for sale.
By the way - some cheek pieces on ebay are offered with a “soft touch” coating option. Don’t bother. Mine started peeling after a few weeks use and now looks horrible.