If buying a Beretta and can’t find a LH model, Cole Gunsmithing (large Beretta distributor in the US) have LH stock sets available. I bought a set from them as getting stock sets here is quite expensive. You can recover part of the cost by selling the set you replace.

The new stock set will need to be fitted by someone that knows what they’re doing.

Once you set up with a LH stock set you can get yourself fitted.