I hope I can find legendary versions or all the new items are basically worthless.

I think all the DLC weapons are unique... apart from the handy saw I've only found one of each

Robot armour and Helmets found rust devils can be re-looted when they respawn, I've also found encountered a couple of them fighting rogue robots you go after at the end of the dlc.

The robot armor on a fat guy makes me look like a developmentally challenged 40 year old out trick or treating as iron man.