Most non-adjustable stocks have no or neutral cast, most newer semi autos have shim and cast inserts to get the fit you need or if your set on a over /under
You might want to look at Turkish shotguns most new ones have very adjustable stocks are unless your planing on shooting tens of thousands of rounds they all seem about the same quality wise, again just my opinion
I shoot a Catma 505 for skeet and other member uses a huglu and another shoots trap with a Canuck.
One thing my catma is rh only, with the grip and palm swell, not sure If they has LH models.
Good luck and keep posting