There are lots of old Winchesters out there for good prices. For a new gun, I would recommend a Marlin. I have not handled one of their new production guns since they moved the factory, but I would hope the quality has not faltered.

As far as caliber, 38/357 is best for a range gun due to economy and light recoil. However, a 44 or 45 would be better for serious self defense or hunting use. An 1894SS in 44 Mag. would be my top pick. Be warned, however, that once you are bitten by the lever action bug you will soon want some .22s, a 30-30, and a Guide Gun in 45/70. Ask me how I know.