One of the problems with those eBay bumpers is even though they are a knock off, the attachment points only weld to the face of the 3/16" thick bumper steel and they aren't reinforced. I've seen plenty of them rip right off on a decent pull.
With that said, I purchased the Manta Ray DIY front bumper from Dirtbound and because I am an overkill type of guy, I threw their attachment points in a drawer and instead used 1" x 2" bar stock that went completely through the bumper and welded along the frame rail so there was PLENTY of weld coverage. I would never trust welding one just to the face of a 3/16" thick anything. Those things can become one hell of a missile hazard during a hard pull situation.