Are you still standing by the NH-L9 as the best cooler for this case, so far? I could've sworn there were a few other contenders if we consider non stock fans
Yes, the NHl9i is the best Intel cooler for the S4 MINI.
There are other contenders IF you make concessions in other areas. I think 30% of the pages in this thread though answer this question in far more detail than I can here. You can watch my video on the subject, and I also have a link in the first page to Cuban's awesome writeup on the subject.
Best of luck!