Well, Chuck is right in servicing the slides.
Most likely the clicking
is from worn attaching parts, i.e. anti-rattle clips, etc.
A high mileage car such as yours should receive rebuilt loaded calipers
as the hydraulics are renewed along with being assembled with all new retaining/attaching parts. You just bolt them on and renew the hoses also, as has been suggested.
I am really impressed with and use only AC Delco aftermarket parts (except for that one set I put on a Merkur