Thanks guys, yeah I know there are a lot of variables but I was just hoping for some guidance which you guys have given. The board looks something like this although the dimensions ended up being 8'6" x 28.7" x 4.05" and roughly 108L after a few small changes.
I'm 82kgs, 5'8" and like a loose board, although this was made to go well in faster, steeper, hollower waves. Less top to bottom and more down the line. At least this is what I'm hoping to get from it. My other boards were meant for anything up to 4' but I hope this will be able to handle up to 6'.
My thinking behind the Sunny's and FG5's. The Sunny's have a large amount of surface area & are tall so should hold well but are pretty upright so should still be loose. The FG5's with the inside foil and long base should give plenty of drive. FG5's have been my favourite fin for years, at least when I was surfing.
I have only ridden quad SUP a few times, first the Naish 9'6" (tanker) and recently an 8'8" custom which I loved so I'm not that experienced when it comes to quad SUP's. Thanks for the feedback everyone, unfortunately I don't have time to test, test, test cos I'll be on the plane Sunday morning and it still needs a hot coat.