Wife rides a road bike with stem shifters. LOVES the frame. The shifters are a bit less loved. We may be moving next year; when we do we considered replacing a couple of parts, maybe putting a somewhat newer shifter on it. "Somewhat Newer" being a pretty relative term, to mean "something with the shifters easier to reach, not in danger of impaling the rider, and maybe but not necessarily indexed".
What exactly would be involved in this, and what would the expected cost range be?