One pleasure I've discovered as I've revisted some of the bike products of days gone by is just how nice the old SunTour shifters were made and how much I really like them for shifting. Many of SunTour's shifters have a nice micro ratcheting action that isn't indexing, but is a good feel, and also adds just enough resistance to make the shifting feel just right. Unfortunately, the shifters only come as downtube shifters or thumb shifters for the most part, making the choices a bit limiting on where you can place them.
But then I found this interesting product as I was searching through some bike stuff: http://bikeportland.org/2011/12/02/local-entrepreneur-dreams-big-with-new-retroshift-system-62994
I think it looks like a great way to preserve shifting on a bike with some nice SunTour components, one of my favorites, or for anyone else who doesn't want/need to have a full on integrated STI brifter. They're not cheap at $120/pair, but could be just the thing to complete that perfect build for an older road bike or even a cross bike!
For a cheaper setup, there's also Kelly's version - it places the shifter in a different position, but still plenty useful: http://www.kellybike.com/2nd_xtra_takeoff.html
Either one preserves the smooth shifting of your vintage gear, and doesn't force you to bar cons or down tube shifters. Now you really can have it your way, and that's what Green Path is all about!