Take a look at Tony Turbo's RST dash set up. He has a Stack for the rev counter and digital speedo and the whole range of Defi gauges and is the best set up i have seen in a S2 (and dam expensive too )

He has the defi controller that controls gauges for: Water temp, Oil temp, Oil pressure, exhaust gas temp, Fuel pressure and Turbo boost pressure. He also got An Autometer fuel gauge and boost controller below the radio and had the Dash flocked and matching interior trims matching flocked

Its EAXTLY how i would do my RST if i had the money