The only one Ive used is an Auto Tap. hooks up to a laptop and gives you every possible parameter
In order to find a good one like you wan't you usually have to fork out some seriouse cash. You could go to your local dealership and ask what they use (they usually have the good stuff), or you can just have autozone check it for free whenever your CEL comes on.
Personally, I've always been partial to Snap-On but thats just me. Expensive as all !@#$ though, but I think they make what your looking for.
Most OBD-II scantools I've seen can read at least some live data, that one looks like it can, but probably isn't capable of really advanced stuff. I 2nd the Snap-on, and theres one I saw at O'Reillys that I want myself that can read advanced stuff also, but can't remember the brand-name or model, and its not near as pricey as the Snap-On. As for what the dealer uses, its probably a Tech-II, and those cost 3 grand for the basic setup, a good bit more if you get one with the CAN kit and/or software subscription.
