Richard, congratulation for launching a new book. I voted for cover ONE, as it reflects the cultural aspect and is clearly Chinese. It though does not have the island touch - possibly you have a similar photo taken in a coastal village on Kinmen with something symbolizing 'ocean', like a small fishing boat, a fishing net, fishes hung up for drying.
I love Matsu islands and have walked all the islands of Matsu and the others. I love their architecture and the way the villages have been restored. The photo has island or coastal feeling - obviously. The small issue is that the architecture could at a first glance be from the Mediterranean coast in Europe.
Wishing you success with your new book