Hi, don't know if you bought your gear yet. I use FX myself. 2018 gear though. Good flies dash so I get to use them a lot as well.
First of all I like both and I am sure you will be happy either way. Differences are pretty slim from what I can tell.
However for slack and unhooking I feel the dash is superior. I have to pull the bar a lot for the kite to react. For looping I prefer the fx.
But again, both are great kites
And since you asked for board as well, I ride the naish monarch with boots and am happy with it. Most of my friends use the stomp though