Looking for code reader diagnostic tool

Hi All

I hope this is the correct section to post in.

As general question to start off with, have a few of you guys purchased your own diagnostic tool? and if so, where in CT can I get one, how much does it cost, and besides the tool, do you need a laptop with specific software to run the unit?

Then, the other question is - is there someone in CT that would be kind enough to help me out by plugging their unit in my car and do a diagnostic please?

Reason for asking is I have just had my car come back after having some work done (attached pic) as the car was doing the normal lack of power, lumpy idle and stalling, etc etc etc. and I'd like to have some facts before going back and making a scene.
And I would like to check if there are any other gremlins that popped up now as the car is doing the same thing again.

and I drive a 2010 320i E90 LCI model

Thanks.