Nice kit Orange Whip. Is there any places around where you can try a couple of sail sizes? I'm 85-88kg and I can get my Falcon lightwind planing in 13kn with my 8.5 Ezzy Lion, and 11kn with my 9.4 NP V8. Seems like a 8.7 V8 should give you what you are looking for.
I recall some asking how a lightwind board does in more powered up conditions. I explored some of its limits I guess. And here's the vid to prove it!
Kit:
2017 Fanatic Falcon Lightwind 159L - 50cm Stock Fin
2016 Ezzy Cheetah 7.5
Wind NNE 15kn - gusts 17-18kn
Waves: Swell 4 to 5 feet plus chop
My take:
Despite not being a top choice for such conditions, 15-17 knots is not a problem for the Fanatic Falcon Lightwind. Not only it is totally manageable in nicely-formed swell and chop, it is quite fun to sail straight lines in these conditions. The Falcon Lightwind just wants to go fast regardless of what's in front and can easily take the abuse in conditions above its intended use. The board is predictable and behaves surprisingly light under the feet but beware, with a 90cm width, it is best to avoid big take-offs!
The video features 3 minutes of uninterrupted continuous sailing footage, so be sur you're awake before watching!