I am left handed and shoot anything I want to, mostly. I have not found the shells flying out the side of the gun to bother me, and if you wear shooting glasses, then I know it won't bother you. You don't have to settle for guns that may not be the most disirable, just because you are left handed, but the Browning BPS is probaby a good choice in a bottom ejection.
However, if you want a Remington 1100, 870, Browning A5, etc. even a Winchester model 12 you can change the safety over to left hand operation. Often you will have to purchase an aftermarket safety, but some guns are reversable. of course the top tang safetys are very nice for leftys, and I must admit, I have hated crossbolt safetys all of my life, because of being lefthanded, but after changing then over, they work fine, still not my favorite safety system, but workable.