IMO the fins that are more upright and have more area in the tip usually offer the most stability.
More area in the base usually offers better tracking.
I'm a big fan of the dolphin shape fin.. but even they can vary a lot.
I think a big 10'' dolphin fin will go well in the M14.
Fins like the Gladiator Pro [great fin] offers great stability and tracking but suffers with manoeuvrability and surfability.
This is what I use in my Jav 14.