Just wondering if anyone has any suggestion on some really good upwind boards and sizes? (not necessarily brand new or current boards on the market)

Rider
12m flat kite, 75-80kg rider and be kiting in conditions with a bit of chop - no flat water

I'd prefer something that isn't directional...I would prefer a twin tip or maybe a mutant if a mutant is better. The board will be specifically used for going insanely upwind and downwind for a Slalom race.