Kode 86, Kombat 79 or Pure Acid 86 will all work. They are in fact more similar than one might think. I'm just a few kilos lighter than you but used my K79 many times with 5.9 and even slightly bigger. If works quite well with a bit bigger fin. It's a super nice board, particularly the lighter 2008 version (2007 Kombat were heavier). Even though you might struggle a bit more with 5.9 on the K79 than on the wider PA86 (or K86), I think that it overall will be a better board for the conditions you sail.
So, K79 is my advice.