I have the same question, so I'll be interested to see the recommendations.
But I do know that one recommendation is to just buy a new barrel (perhaps around 24") that already has rifle sights on it...because that may be cheaper than having a smith install sights on your existing barrel (which I'm guessing is the 18 1/2", same as the 2nd barrel that I have).
If it is too difficult to install sights myself, or if the sights alone will be almost as much as a new $100 barrel, then a new barrel might be the direction that I'll go in.