@Randy_Goodwin, Sorry you are giving up. Brakes can be fixed, they are not rocket science. Your problem is a bit confusing though, I think that it this time, if I were working on it, I’d put everything back original.
Some tips for the future though. You started this by tagging onto an old thread and them moved to a new thread, that it OK, new visitors often do this, but it would have helped to have inserted a link to the thread you originally started with as it has some important history.
Your problem started immediately after replacing the front calipers and rear wheel cylinders. At this point you should not have done anything to the rest of the brake system. First rule of mechanicing is if it fails right after you fixed it, you fixed it wrong. You may have gotten defective parts or a part that was not a direct replacement or something else went wrong. You go back over everything you did, you do not go looking for more bad parts.
BTW, looking at the picture of your calipers, the first thing I thought is they were not the correct calipers. That is why I asked if they were yours or just a stock picture you got from somewhere. I would go to a dealer with your VIN number and have them look up the correct calipers for your vehicle.
If you want to do it over the internet, go to https://www.gmpartscenter.net and enter your VIN. Then get the GM part number and cross reference it to the calipers from your supplier.