try DATAMARINE
When I bought my 25 it came with a datamarine masthead unit for wind direction and speed. At the time, the fin was missing from the vane. I had no idea how old the unit was or who made it. I found a model number on it and some info for what turned out to be an older company which they had absorbed. I contacted datamarine and was able to purchase what I needed to repair my unit. I later broke the masthead unit's wind cups through an act of my own stupidity. Again, I was able to get what I needed from them. I have had great service from datamarine and really like the unit that I have. It has one guage mounted next to the companionway with a toggle switch to select between windspeed and wind direction. I generally leave it set for speed and just look to the masthead to read direction. Admittedly, I've done no research into other units but am satisfied with what I have. Try this link or a google search for them. I think you'll be happy. http://www.maritech.com/