4xInnovations,
I've welded 4xinnovations for my truck and my brothers. I've done trailgears - garbage, and Marlin Crawlers.
I prefer 4x innovations because they come with frame plates and gussets, frame plates distribute the damage from a slider hit instead of denting in around the tub into the frame and gussets just further strengthen it.
The other two options didn't come with frame plates, Marlin Crawlers sliders did come with gussets though.