Which tires should I buy for an old road bike?
It depends on how you intend to use the bike. If you're intending to race, you'll probably want something lightweight and very grippy. If you're commuting or touring you should tend towards the durable end of the tire spectrum

With a nice steel frame like that you'll get lots of comfort, so it seems to "fit" with putting wider, comfortable, durable tires on it.

A wider tire is more comfortable with the only disadvantage being that it is a bit heavier.

If the bike originally had 28mm tires, I would expect it to take 25-35mm with no problem, but check the rims for any other indication.

The two you've listed don't have a great reputation for durability, so it may be worth investing a little more for something that will last longer and save you the frustration of punctures.

Consider Continental Gatorskins or Schwalbe Marathons. Both are more expensive, but offer good puncture protection which, in the long run, shortens your journey time more than a few grams of weight saving.