Highline -
You can scan you car and get the part number from the scan part number will be under Address 17: Instruments
Cost of Highline is between £200-£250 retrofitted. If you can source a HL which is for your car you can save a bit on the cost.
Phil Miller can source some HL clusters and can code, 970, 971 and 972 and some 973s
Kalu can also source HL Clusters and can code the 974s
I think ML clusters end 96* and HL end 97* basically when you know your midline cluster code change the 96* to a 97* to know what to look out for.
RNS Version C -
£500 max and you can retrofit it yourself