I'm going to work in the Greece (Ionian)soon for the summer and would like to kitesurf while there. I am a beginner/intermediate and weigh 10 stone. I have read the average wind is force 3/4/5 and would like to know what would be the best kite size to purchase to get the most time on the water.
Any help will be much appreciated!!

Force 3-5 covers quite a wide range... From 7-21 knots, You are unlikely to get out in a Force 3 really, even if you are only 10 stone so you'll be looking at something for Force 4-5... Everyone here will say get one of the new Bow kites (I'm not going to say which one as I'm not joining the xBow vs Sonic argument!) as they have a really wide wind-range, and loads of other characteristics that make them ideal for beginners (Safety issues, relaunching, depower etc etc). I would imagine a 10-12m bow kite would get you comfortably up and going at the lower end of a Force 4 (11 knots), and although it would be OK in a Force 5 once you are more competent, the upper end of a Force 5 will be a bit too much whilst you are learning.

Enjoy.
Al.