i'd put campy (gran sport or nr) down tube shifters on it and an nr rd, but that's just me. i can sometimes find the shifters on craigslist for $20 and an rd will cost $40ish on ebay. the uglier, the better, 'cause after i overhaul 'em, they look and perform as brand new.

the rd should have a patent year between '70 and '84. (at least, that's what i'd look for.)

if your barcons are suntour, you can easily sell them on craigs for $30+ or on ebay for more. i love making this switch with motos, 'cause you can usually do it at a profit, especially if it's vintage cyclone for record.