I have been using the Vector Canefire G-10 fins for 2 years now, -and I can only say that I'm more than satisfyed with their performance on any of the Isonic boards. I use the Canefire G-10 model on all of my boards (from 32-48cm)
Yes -,, I'm on the Vector fins team, but one thing you cant go on compremise with is the fins for your boards. Thats why I have tested (and still is testing) a broad range of fins from different brands (carbon, molded, G-10 etc), to be sure to have the best, but all the time without quistion the Vector fins has the best feeling and performance.
For the Isonic 111 for sure the 42 Canefire for light wind will be great, and the 38 for high wind.
By the way most sailors trying my complete gear setup, nearly always comment's on the fin as the first thing, to tell that they find it slippery and fast, but also very easy to sail.