I didnt find any weapons higher than a green that i could equip. Found blues but couldnt upgrade. As far as attachments. In the upgrade tree. I was able to attach/unlock multiple scopes for my rifle. And my shotgun had dofferent kinds of ammo. Amongst other thing. U wont be disappointed.
( we were level locked at 8 for the testing also level 20 gear on vendors. Looks amazing)