Its a tough one with your weight and the conditions. 131 is probably the nicest size, but given the low wind you may need the extra size of the 134. They are pretty fast boards so you can get going quite quickly on the 131. Don't suppose you have the option to try before you buy.

you could go for a board with a bit of extra width for its length, to get you up and planing in the light winds

i highly recomend the underground flx. i tried learning on an old switch 142 couldnt do anything. gave a burn on a 128flx and was going back and forwards in about 10mins.
very good in the chop and plane pretty nicely too. im in love. im gonna go touch it............

yea flat to small chop mostly, no breaking waves. Riding overpowered? well most of the time I ride on the 12m, but if the wind is a bit less than usual i don't need much convincing to go to the 16

139x41 Nobile 666.

Im the same stats as you. I made a big mistake and started off with a 0G 133x34 (20mm fins) too skatey.

what skill level?

im 80kgs, in 10-15kn down on the river (flat flat) and a 16 i used to ride a 122 underground... not much difference to the 128, the 128 feels a shade big.

ive tried 132's+ and they are big ass heavy chunks of crap imo

dont go too big unless your just learning

Skiddz,

I ride the 07 Thorn 131 and am 90 kgs. I know everybody rates their own gear but I can honestly say, being as objective as possible, this is a good board. They are very quick and will keep you upwind with ease. I can hold ground in 17-18 knots on my 10m SB2. Based on your lighter frame and kite quiver I would suggest that you should easily do the same and perhaps it may even be a little big for you. Also given those conditions I would figure you would be riding wakestyle/freestyle. This is my direction and these boards are very good freestyle boards with good pop. I guess the best is as some have already suggested, try a couple if possible and see what is best going to suit you and your riding style.