Hallo Windy Miller! Please look:www.designlessacher.com.
That what new is, Wave Weed Fins. Wolfgang
Check out SELECT fins - Mark at SurfSail stocks them, they have some sweet wave options and come in Powerbox. Also Northshore Maui have some really good wave fins in bigger sizes. FYI, the EVO 105 comes with a G10 Drake 26cm that looks pretty sweet and can be converted to Powerbox.
You should not always equate length of fin with wind range though. Base width, stiffness, rake and chord all play a role when it comes to wave fins. Just look at freestyle fins - rarely do they get bigger than 22cm but are regularly strapped to +100Lt boards that are designed for snappy tricks in marginal conditions. For them it's allot to do with base width to get them to pop.
Last point is the most fins that I have had to repair have been bigger than 24cm, reef n rocks love em.
AB....
Funny I had this dilemma at the Gloo 12-14Knots 126 Litre JP SuperSport, 6.7m sail and all the fins I had were slalom and a bitch to turn.
One of my mates had a Fanatic 34cm weedy which was just the job, it looked more than 34cm's tho, turned well and gave me plenty of lift to get the board going.
And this was the biggest of the range I think they went down in 2cm increments.
This fin made my day 
I have a Lessacher 36cm Duo Weed and use it on my big board. Its a great fin and I have gotten 24knots + out of it.
Some of the other guys that I sail with have the Chameleons and they seem to like them. Very few problems with spinning out. I know one of them wants to get another one in a smaller size. I am going to be looking at one myself for my smaller board.
You buy them direct from Wolfgang. Just email him and he can give you all the details.
