Hey! Depends on how much you weigh and what conditions you get at your local spot. Im about 70kg and use a 10m switchblade and kite down at st kilda beach most of the time. If it gets above 25knots i can get over powered but most times im out it does me just fine, even in low wind conditions.

So if i was you take this as a starting guide...
- How much do you weigh
- Average wind conditions where you go

And talk to your local shop they usually have a good idea of the local conditions and a good place to start out.

Hope that helps

Get down to your local shop and get a lesson from that you should learn about local conditions and be given good advice on kite sizes for you weight etc, as well as a better understanding of the sport..
Cheers Dave