its not a definitive guide (sorry dizzie!) but all i know is that when i put mk4 calipers on the rear of my golf you did have to have the handbreak cable running from underneath and to the back of the caliper.
so i assume if yours is the early type then in theory a later handbreak cable would do the job, along with the correct conversion hose.
word of advice though (this may be obvious): the mk 4 calipers are apparently self adjusting to compensate for disc/pad wear so if you are getting them off a crash damaged golf you need to make sure they are set up properly or they will need setting back to factory standard.
when you have the caliper in your hand and move the handbreak lever you can see the piston moves in and stays there. don't play around with this as the first set i had were played around with by the guy who shot blasted mine, so by the time they were fitted i couldn't get them to work properly, so i called c&r, who i bought the conversion hoses from, and it was them that told me that they needed to be put back to factory as the self adjusting mech was assuming my pads had worn out and were not doing what they were meant to do. i asked vw about this and they looked at me like i was an idiot for putting mk4 calipers on a mk2, so in the end i just got a second set didn't touch them (other than a lick of paint) and bolted them up, worked first time!
never tried mk3 ones but as said above i think they are just a direct swap, but again would probably need the longer handbreak cables to pull the lever from the bottom/back. i seem to remember in 'the golf' people not realising the difference between early and late and fitting the mk3 calipers upside down as this looked the same as early mk2 ones.
you'll sus it out!