Most long arm sets I've seen have a bolt on bracket either replacing tranny crossmember or in addition to it. They also have upper arms mounted in a different than stock location. Those brackets welded to the unibody like that do not look safe, unless its already plated/reinforced and I just can't tell. Long lowers and short uppers makes me think it would bind up when trying to articulate, different axis of movement and rotation.
I agree with the other guys here, it looks homebrew.