Hi Chris, and welcome to the club..

Yes, there is a common problem on 92-94 cars regarding the rear
calipers.. it is the handbrake linkage that siezes... but applying
copper based grease and working it in can give a cure that will last
for years if maintained.

I would doubt that this problem would exist on later cars... but
apparently it sounds like yours does :(

If nothing is physically broken, then you don't need new calipers..
Jack up the back end and take off the wheels.. use WD-40 to free off
the linkages, and then apply some copper grease.

Next, if the calipers are anything like the older ones, there is a
blanking bolt on the back of the caliper that you remove, inside is
an allen bolt.. wind this in until the pads touch the disk, then
back off 1/2 to 3/4 of a turn.. the handbrake adjuster on the older
models is down the side of the lever under a cover..
Do not just adjust the handbrake to take up the play, without
adjusting the rear brakes first..

New calipers cost about £100 each, so try to fix these first :)

Hope this helps.

John