I am a lefty...and have 2 brothers that are also lefty (only one of them shoots lefty tough)...there are several good lever or break action guns that may work well for you...Marlin, Winchester, Rossi, H&R, NEF...and so on...but as many point out, eye dominance is important (I shoot left handed because I am left-eye dominant...even though I am right handed...as is my father oddly enough...and he shoots lefty as well). I also think safety is important...I know it's more costly, but considering buying them separate rifles is probably the best choice...or a lever, pump, auto, break-action that can be passed down...but I wouldn't try to teach the lefty to shoot right handed.