The windrider is an interesting idea...maybe not a bad choice either. The one thing I've heard about tris is that they have a tendency to pitchpole in large waves because the bows are very fine. Having never been on one or seen this happen, I can't confirm this. Hobie cat also has a trimaran, I think the windrider is a more popular tri, from what I've heard.

Also, I wouldn't worry about the local shop for parts. A lot of things are relatively standard. What isn't you can always order. I don't deal with the most local dealer to me (long story). The local dealer is 30 min away. Instead I bought my boat from a dealer about 5 hrs away. Whenever I need anything, I just send him an email, and it arrives in the post.

Also, regarding the 16, it si true there are a lot of ppl who passionately love the boat. But I think that for every person you find who passionately loves it, you'll fidn someone who passionately hates it.

-Justin