For the serious collectors with a LOT of money to spend :
There is a beautiful  Paiwan long house beam on sale now in Yungkang Jie, Taipei.
It is of the best quality, and part of it has even been photographed in one of the local edition of Chen Chi-lu's books.
It's very long and very heavy. If I have time, I can go back there and ask if it's possible to take pics.
On appointment only.