I have many pairs of Freediving fins I would be willing to let you demo...and you could get any of these from the Florida Freedivers shop....
Much of choosing the best fin for you, is about how fit your are, and in how good you are at changing the "shape" of your kick--with freedive fins, this is essentially a way to CHANGE GEARS...
I have some Carbon fiber Mustang C-4 fins...these are soft, and easy to kick...very high end....some DiveR's, which are the fastest, but also require significant cycling type fitness for the effort to feel non-existent....and several in between...
I also have Scubapro Jet Fins and Hollis F1's, and Force fin Excellerators....which when you try the 3 of these, I expect you would favor for their higher tech performance.....
What size feet do you have? We could do this at BHB, and at the current change before high tide, you will get a great sense of how each does at going "cross current", up current, with current, etc.
You should demo fins!!