In the price range you're looking in, be sure the wheels have a machined braking surface. Not all low-end wheels do. I made that mistake myself. It makes a big difference in braking smoothness and brake pad wear.

Second, be sure they fit. Standards in both hub width and wheel diameter have changed since 1981. Not all older bikes can fit new wheels. There is also the matter of older freewheel vs. the new freehub. If you're shopping at an LBS, they should make sure the wheels fit for you.

Kool-Stops make a difference. Use the salmon ones for wet weather, black for dry. (Salmon works fine in the dry, but black is not so hot in the wet.) They're a cheap place to start.