Andy- I looked into these modern dashes even fitted them to a couple of cars. I didn't like them they are certainly not in keeping with an old school Saff. What you see will set you back about £1800 give or take.
A full set of decent gauges show everything you require although they are not cheap. As for a Speedo/Odometer again I choose a Stack with Rev counter combined. Other gauge is Boost pressure.
At least look at a car with this new fangled type of dash before you decide they confused the hell out of my old Brain .