I just rebuilt a 1989 Cannondale ST400 with triple crank and 6 speed freewheel. I used new Shimano SL-BS77 bar end shifters (in stock at JensonUSA) in friction mode controlling vintage Suntour 3040 FD & RD. Works like a champ and comes with all the parts you need to do the conversion including cables and housing. Took me about 45 minutes to mount both and that was taking my time.
I built them into Venzo drop bars that I added to a flat bar to give some additional ride positions. Look them up on Amazon. I can't post the link because I don't have 10 posts, sorry.
The whole conversion includes a stemless adapter and adjustable mount, flat bar, bar end climbing grips and the Venzo drops. Lots of adjustability!