Righto bite me so you give me all your specs not in metric...notice my name...we use metric here that's why I asked. Hang on I will get the conversion as I asked....
Righto 85kg, in 8 to 11 knots...okay let's begin. Hang on 70 F...bugger me....21 degree so fairly full wind I'd say...
Well actually the advice above is spot on. The more the aspect the less the static grunt. That being said don't discount the new dyno from north. Get in touch with puertz on here as he made some interesting comments about the static grunt of this new incarnation and he is near 115kg and rides in the shit wind capital of Australia (Darwin).
But ultimately the above post is correct. High aspect kites don't dig current, nor something like seaweed, they want speed in the wing. Once they have that they will smoke lower aspect kites for pointing upwind...but there is also a trade off in riding style....
Look I'm 76kg and have a crazy fly cruiser pro 145 by 44, so with our weight difference and your wider board lets call it even. On the NEW zephyr (wish people would stop talking about the old zephyr the new one is a completely different kite, not similar, might as well be another brand and make), really I'm looking for 11 knots minimum to keep ground. Not having a great deal of fun, but hey I'm out there. Really I'm looking to start at 13. 13 to 15 I'm chucking down some stuff and really having fun. 15 to 17 I'm smiling, powered, going big, loving it. 17 to 20 I'm cranked and having a total blast....
But 8 to 11 knots (11 to 13 mph) nah the zephyr won't cut it mate I will be honest unless you get yourself a race board or a light wind surfboard.
The zephyr is not really a light wind kite, its a medium wind kite that performs when I think its worth getting out there anyway. But it has an extraordinary top end delivered by the infused edge DNA.
Speaking of the edge, have you considered the 19m edge. Now that's a beautiful kite and puertz mate tony uses one in Darwin, talk to them about it. I rode it in Bali (I have owned and ridden the 13, 11, 10 and 9) and they did something special with that 19. Worth a punt, may be big enough to overcome that static problem...but maybe not. Bloody quick turner to.
Of your choices My bet would be the fat lady, even though the NRG does afford more static grunt that you think. Did on the 10m I tried anyway...but haven't been on the big ones.
Personally I'd put my money on the new dyno all factors considered and from what I've spoke to puertz about, he's a bloody good rider, honest as they Get and will tell you how it is. Also I know crew who love the fat lady and I'm sure its a wickedly fun kite, but light winds and low aspect, that just doesn't make sense to me personally, the physics is all wrong. In my own head anyhow..lol
Goods luck.