The latch boxes are all over eBay and Amazon for under $100. There are some vendors with the torque tube already welded in, for around $250. There are several who sell the latch boxes and QA plate. You would cut the eyes off of the existing bucket, weld the latch boxes to the plates with the eyes. Then add a torque tube to keep both sides together. Weld thee plate onto your old bucket and your off and running.
If you don’t weld, talk to a couple of shops who do. I can tack things together so they stay in place. But need a lot of practice before I would be comfortable welding up something critical. One of the local shops, who also sells materials and welding equipment, cuts me a good deal on welding up things after I tack them together. I can grind off paint, and bevel edges as well as he can. And my spending a few hours doing the prep, makes the cost to have a certified welder do the critical welds, is actually quite low, if he just gets to weld, and doesn’t have to do prep work.
Last thing I took in was the quick atttach off my loader, the guide for the right pin had popped loose. Factory only had about a half inch bead on one side of the guide tube. I cleaned up the one that was loose, then ground of the left guide, and cleaned it up. Then tacked both of them into place. Wrestled it into my truck, and went to see the welder. Owner said sure, shop rate. I asked him where he wanted me to drop it. He asked if I minded him welding on the tailgate. I backed up next to teh welder, he hooked up, and ten minutes later he was done. $40 out the door, and a can of spray paint It was done.