I can't help you too much but I think the standard side fins the board came with, M7's, are too big unless you are in large surf, over 90kg or both. I only recently tried experimenting and took the side fins out, this freed up the board significantly and it also goes quite well with a GX fin in the side as the surf picks up. I haven't tried specific SUP fin sets, I just grabbed the GX's off one of my short boards to give it a go.
I just took the side fins out and left the original fin in, I dont think you need a big fin for small to average size surf. If it gets bigger change back to side fins, or better still surf a smaller sup.
