Now if I got it right:
BeOS dano is actually a leaked version of 5.1, which I believe was never released, due to the company closing for business.
It has a very dubious (and as yet still not cleared up) legal standing, and I think most sites are steering clear of it for that reason, which means that you would probably have to go warez hunting for it.
All I really know of BeOS now, is that the OpenBeOS project is trying to build and improve upon what was left (link on the front page).
That is yet another OS I have fancied trying, but as my computing skills are not at that level, I still have too much to learn, and no time to do it. Oh well, there's always tommorrow.