Reboring a Barrel to 50-70

[Flash Pan Dan]

I have been considering having my 40-65 Pedersoli Sharps bored out to 50-70 for hunting. To what bore dimension should I have it bored? I would like to have the chamber reamed for paper patched bullet use. Can someone point me to a good reamer to use.
And while we are at it, may I have your opinions on reboring a barrel. Have any of you had experience with it and who would you recommend?