I'd go with an Athena groupset... from 1990. Because this would be a rando bike if I were getting one, I'd put Nitto Randonneuring bars on it, and a new Sun dyno hub in the front, laced to V.O. rims and shod with Compass tires. Add a Brooks Team Pro saddle, a decaleur and small bag for the front, Nitto mudguards, and Shimano A-530 pedals.