Looking for a T4 Topaz with the roof bunks.

Hi all. After much research we have established that the Topaz could be our ideal van. However we will need the roof bunks. These seemed to be a factory option and there here doesn't seem to be many around. So I thought I would put this up just to see if anyone is thinking of selling in the next few months. I am considering modifying a 2 birth as I am pretty sure it won't be difficult, if anyone had done this I would love to know more about how difficult it was.