I purchased my first set of rear bumper tie ins. I got them on eBay from gpfabrication.
They're 1/4" thick steel. I like the fact that the provided grade 8 bolts come with tabs welded on them. Holding the tabs make it easy to guide the bolt inside the frame, through an opening at the bottom of the frame. Also, the tabs will rotate into the frame and make the bolts captive for easy nut tightening.
They don't come painted. I sand blasted them with 80 grit Aluminum Oxide. This gives a fairly rough texture.Then sprayed them with Rust-Oleum primer and semigloss paint.
Installation was a breeze. You can see how the tab helps you guide the bolt in the frame.
They were $34.95 + 10.50 for shipping. They were shipped fast. They are very solid.