Just get the Aeroforce Interceptor gauge. It has two analogue inputs for any sensor you want. I have mine, and it's freaking awesome. I have no need for another oil pressure gauge (my car already has one).
I'm not sure how much that "Scangauge" goes for, but the Interceptor gauge goes for $240 and displays a lot more, plus it mounts in gauge pods for a cleaner install.
Just my $.02.
Interceptor OBD2 data stream gauge and scan tool by Aeroforce Technology