Just to add one more vote - the Ruger no. 1. No real reason, everyone else's comments have got me nodding like a bobble head.

If there is any desire to go for cowboy nostalgia, then for sure the 1885 would be the style to follow.

And to answer the urge for bigger is better, the 45-70 is a nice caliber to consider as it is already big and easy to rechamber into 45-90 and 45-110 and... 45-120... well what? surely we'll bump into some mutant hog one day...