What about either a 25-20 or a 25-35? It might help to know if this was going to be a deer-first, small/varmint game-second, or a small/varmint game-first, deer-second piece. (Hey, I think I just found a reason to get more than one such "dual purpose" gun... <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />)
Either way, either should do the trick. The 25-35 is deadly on deer and with handloads can be good on small/varmint game. The 25-20 is the reverse: deadly on the little stuff, adequate on deer (with handloads, and a good shooter, and the right shot).
That said, there are no flies on the 32-20, 32-40, 38-40, or 30-30 for the same purpose, granted you know what you're doing on your end, and you probably do if you're asking this type of question.
Hey, there's nothing wrong with the suggestions as to the .357/38 set-up, I just figured I'd add a couple of comments and maybe a few options to the mix.
Should be interesting to hear where you come out on this one...
