'82 CSR650 Needs new chain and sprockets - advice and suggestions please?

My CSR650 is slowly up and coming as a winter project.
Among the items that I need to replace are the chain and sprockets.
A few questions please?

-I read all about new conversion chains from the old 630 to the new 530. Not sure how that applies to my bike.
-Can I assume that one should always change both sprockets with a new chain to avoid premature chain wear?
-I swapped a chain some 20 years ago (LTD440) and just ground the old chain off and installed a new master link. Anything changed all these years?
-Best place to purchase a new set please?

I have basically the same motorcycle & it seems a little high revving to me.
When the time comes, I plan on going with a 16T Fr & 40T Rr 530 setup which will lower the revs slightly. but not a lot.
A 16T 530 sprocket is about the same diameter as a 13T 630, but slightly larger which is a good thing. I'm not sure if a 17T fits.

GearingCommander

JT Sprockets