Frankly, there is no point in buying an expensive one. A regular transparent cable with an FT232RL chip is enough, it is reliable.
Yes, as I said, you need the SP-Daten files for E90 (E89). If you are familiar with Mercedes coding and programming parameters, NCS Expert (coding) and WinKFP (programming) are similar to Vediamo for BMW, and SP-Daten files are equivalent to CBF and CFF files. Without this you will not be able to change the coding in BMW. I don't remember the exact path to the SP-Daten files in the ISTA-P directory, but they are easy to find. Simply navigate through Explorer, always selecting the largest folder, until you find the "E89" folder. Then use the BMW Coding Tool from the BMW Standard Tools package to update SP-Daten by selecting the "E89" folder you found.