Thought I'd share a gauge I recently picked up from
http://aeroforcetech.com/I don't know if these are officially available yet, but I got a beta version and so far it seems to work pretty well.
The gauge shows some of the Subaru SSM parameters, as well as some conventional OBD parameters such as Target boost, Boost relative to sea level, Engine load, Current gear, IAM, Fine Knock, Feedback Knock, Knock Sum, A/F Learning, RPM, etc. It also accepts 2 auxiliary voltage inputs.
You can graph 2 parameters on a scrolling graph, which is particularly handy for target boost/actual boost, or show 4 parameters on a bar chart. Otherwise 2 parameters are shown simultaneously. You can also set a warning light to any of the parameters, which I'm using for IAM to know right away if the car has significantly pulled timing.
My biggest issue with it is the display. It's available in different colors but lacks contrast, especially when it's hot outside. I'm hoping they can develop an OLED in the future...