there are two types of instrument cluster, 1 with 2 electrical plugs, and the other with 1 electrical plug. one says VDO on them & has no light in the temp gauge. the other says Motometer & has a red light in the temp gauge. so just look for the same as you have either VDO or Motometer
you can use, 120, 140 or 160mph clocks. just need to select the correct drive for end of speedo cable. there is only 2 drives for speedo cable, red & white. red is for 16v plus i think 120mph clocks. but even if you get the wrong drive they are only a couple of quid outta VW