I have been using the MFC K-ONE 24 and 27 with my 5.5 and 6.0's on the 86 Kode. I have to say the 24 is a dream! fast, when and if it slides out.....it pops back in with ease. I have the 27 there for my 6.0, though if i can i will start on the 24 before switching up.
my feeling has always been...board manufacturers make boards....fins manufacturers make fins. as obvious as this sounds as good as some stock fins are they are often the most under rated piece of gear when people start talking boards. your style of riding can literally make or break a fin thus a board. try MFC. i really think you will be bumping and jumping with ease and pleasure.