The Grand Prix is a nice frameset, a ten-speed from the Bike Boom era, so probaly with 27" wheels. If you convert it to 700c you'll need long-reach brakes, but in exchange you'll be able to fit fatter tires (32c or maybe 35c). The problem with Raleigh is that their bottom brackets and headsets were not ISO threaded. They were such an important company that they had their own standard, and so if these parts are shot you'll have a hard time trying to get replacements.
The Peugeot, OTH, is probably of Canadian built, so BB and headsets are all ISO.