G'day block,Depends on how often you want to kite, at your weight i'd say it would have to be at least 25 to 30 knots to get goin on a 10 meter ?.I'm around 80 kgs and have a 10m needs to be 15 to 20 knots so goin to try my 12m next decent NE 
I'm about 90kgs too and I used to only have a 10.5m core gt. That was a seriously grunty kite and that was all i rode just changing my board. There were other 10's that did not have the same low end so choose your kite carefully. I did miss a few days in the lighter wind days but not that many and on the super windy days I could have done with a smaller kite but beggars can't be choosers.
I decided to return to a 2 kite quiver and now ride a 13m and a 9m.
Hope this helps
Boyler
Hey blocker - there are a few variables to work out what is the ideal kite for a particular wind speed: and I'm sure that I'll forget most of them!
What is the kite (year brand and size)
What is you skill level
What is you body weight
What size board are you aiming for - makes a difference if it is a TT , or a surfboard style.
All that aside at your weight on a big TT a 10m kite will probably get you going at around 16 knots with an upper wind (skill level ??) of around 25 knots - then you are going to start to feel a wee bit out of control !!
On a small TT (ie 128 to 133 length) you could probably add around 3 knots to the lower end range - say 18 to 20 knots and about the same at the top end ( again depedning on a reasonable level of skill)
Please take this as a guide only as local advice will always be better than a website yaka
Ok so just read the prevoius post - location is also important!! As a 92 kg kiter I run a 3 kite quiver to deal with 10 knots to 35 knots - a single 10 m kite isnt going to do it !!
So it also depends on your location - if you have consistent winds one kite may do - but most of us have 3 to get away from the wife LOL
I really appreciate the help from both of you, I don't have the kite as yet. I found one on gumtree for sale and it sounded like a good deal. To be honest I have had only one lesson but i am so keen to get started, I know I should not rush into buying but after feeling the adrenalin on the first lesson nothing can stop me now.
Steve
Hi ya Steve - welcome !! I'm not sure where you ride and what might be you "normal" wind speed - but as i said at your weight ( I'm the same) a 10m kite is not for the light days nor for the big days - most people get a 12m kite which suits most beginners in most locations - as the intro kite.
But thats a very big generalisation - lean on your instructor for some great direction for your location.
Thank you again for the great advice from the four of you. I'm going to take your advice and talk to my instructor.
I'm from the Byron Bay Area and now I'm thinking of going the Gold Coast tomorrow to shop around, not enough time in life to sit around without a kite. I want one now. This kite I was looking at was a Ozone c4 2011 complete kit never used. Seemed like a great deal but not the right size for me at the moment. Seemed to good to be true for the price. $1150 for cf board, harness and full kit.
Steve
2011 10m c4 is an awesome kite. i have it and its my most used kite. i use it 18-28 knots. the sweet spot being 22-25.
ps im 82kg.
your prob need to go to a 12 at your weight for 1 kite quiver.
Lamb chops 
is on the money, it would be wise to follow sound and proven advice - apart from escaping the wife 
Just be sure to include a red one 
Blocker,
I weigh in at 96kg. I run a 9 and a 12 and they have served me well.
Spending that little bit more to get two kites will give you a lot more water time. I remember sitting on the beach watching other guys when it was blowing 25 and all I had was my 12.......... very depressing.
Am now looking at some of the 14/15's to get out on the really light days but thats another story.
