Can anyone suggest or recommend, adaptors necessary to connect an Apple 20 inch Cinema Display to the current 2017 27' iMac, as a second monitor. Many thanks in advance. Based in the U.k
A USB-C to DVI adapter like this one is all you'd need. The display does have a FireWire connection as well, but doesn't need that to operate - only used for pass-through to the FireWire ports on the back of the display, so it's fine to leave it unplugged.