Anyone have any suggestions as to what diagnostic scanner to buy?

After my hard start problems, seems to be better now but I don't know why, I want to find a scan tool to interface with my laptop. I saw the WITECH VCI POD For Chrysler Diagnostic Tool but there are no reviews. I also saw several bluetooth/usb adapters for much less money but I am not sure they are much more advanced than the OBD code reader I already have. I want something that will give me reliable diagnostic information. I am capable of doing most wrench turning but guessing on what sensor is taking a powder costs a lot of time and money.

2006 KJ 90,000 miles with trailer towing package. Green Diesel program installed.

http://www.oemtools.com/homeproducts/chrysler.html

The 1st one is what your looking for.