For the money $400 and lower you will be able to get OBD II genaric code reading and a list of the translation of the fault codes. some will claim to show you datta,but this datta isn't real time and not accurate.
For example to get the datta streaming you want,technitians spend up to 6k on there scanner then another 5k for a lab scope to pin point and these tools stay up to date for a finite amount of time then cost another1000 or so to update.
So in he world of automotive diagnostic equipment is definately a get what you pay for deal
It has become so expencive that many independant garages aren't staying curent.
There are companies that are selling software packages and cables to use a pc to get and read datta. one i'v heard about is called EASE.