You didn't say what you wanted to use it for, or what your budget is.
Now if it's for any of the sporting events, trap, skeet,sporting clays, etc and your budget is big enough here's an American made shotgun that comes with 3 standard LH stocks or you can go direct to the factory in WI and have the stock fitted to you.
I did the latter and have never had a gun feel as good as the LH TA-Max O/U trap gun I now shoot.
There are people who feel lefties deserve better.
They're out there, you just have to keep looing.
Good luck.
http://www.kolararms.com/competition-shotguns