My 1973 Raleigh Super Course has standard English threading in the bottom bracket, as does my friend's. His has proprietary Raleigh threading in the headset. I don't know if mine does, I've overhauled it but did not check out that aspect; the headsets on our Supercourses is to outer appearances identical to the headset on my early Sixties Carlton, which has standard threads. Raleigh headset spares are easy to come by.
Supercourses ride nicely and are both practical and rugged. Whether or not the one you have found is a good deal may depend on where you are, what else is available, and how much effort would be required to seek alternatives. In some places, a VGC Supercourse on sale in a shop for $150 would be a fantastic deal, especially if the rear derailleur has been replaced with a Suntour or Shimano. They make good single/fixed bikes, too.
Chris Barbour
Boston, Mass.