I don't know how genuine this post is seeing you and realplayer are having a nice dig at each other in another thread, but I'll take your word for it.
If you get a 10 or 14m, you are wasting your money as these kites are too close to the 12m you have. In general, you buy a kite you go up or down 2 sizes. aka if you have a 12m, you grab an 8 or 16m etc.
No one frankly knows what wind will be around during summer as this summer (05/06) was honestly very very sad compared to the previous summer (04/05) when I was just a spectator. The wind has become less predictable and just overall pretty yuck compared to previous years. If you want to be powered in 14-17 knots nicely, grab a 16m; however if you would rather get out in about 23-28 knots, take the 8m. Or preferably, get both

Goodwinds and happy choosing [}:)]
Elizabeth B8 - Wello Kiter