I'm between 85kg - 90kg
Had a switchblade 3 12m (18months ago) that got me going from just over 15knots to almost 35knots - I would definitely look at a 9m SLE/bow/delta or even a grunty 8m as high wind option so you can change kites at around 22-25knots and feel comfortable from 22 to 35knots. The 12m obviously won't be enjoyable over 30knots and a 8 or 9 in high winds would be a mega fun kite to throw around in any conditions flat (chop) or wild surf!
I'm in the same dilemma myself - just bought a 12m 2009 Eclipse Kima - will need to buy a 9m to handle the stronger days and use the 12m for 15 - 25knots which has been the majority of our wind recently (last 12months) on the Gold Coast

. I think you guys get slightly stronger sea breezes in NSW

than we do so a smaller 2nd kite would be a must....