Fabricated trailing arms

[foxhole]

So I want to make my own kustom trailing arms for my truck and was planning on tapering some box tube so it goes rectangle to square with some styled reinforcing cutouts and running large rebuild able heims at the front. Was thinking of relocating the airbags so they mount to the axle so i can outboard them a bit which should also make the bag act like a larger bag as far as handling is concerned and reduce body roll. Anybody done it? what are your opinions? I'm looking for every conceivable drawback before this leaves the drawing board.