I get each tormented boss drops same items the normal ones do. But as far as Uber uniques do all tormented bosses drop the same % chance of all items?

It should be same % chance, but last season Zir was the best based on my own Experience. Also less required mats to spawn tormented Zir. There was a nice Reddit thread, where someone posted statistics based on ~100 runs and drops (this was S4 though).