Panaracer Paselas are a good choice--I've used them almost exclusively for four or five years and like 'em.
As for the fit, if there's a LOT of room, you can probably eyeball it. Bikes from that era were heavily race-influenced, though (for marketing purposes--they didn't suit the needs of most riders), and one of the drawbacks was that there wasn't much room between the forks or under the brakes for large tires.
Why not ask at a bike shop? Tell them you want to know if the tires will fit, and if they do, you'll buy them. You may pay a few dollars more than ordering on the net, but you won't have to pay shipping and you'll have the tires that day.