Four 16x7 OEM GMC wheels. These are six-lug wheels with the 6x139.7 (6x5.5) bolt pattern. I believe the model number is ALYGF013U30. They were the standard wheel on various pickups and SUVs from 1992-2000. The tires are absolute trash. I think one tire is a different size from the other...
I think PSA has a room full of gorillas with cheater bars torquing their barrel nuts. You should be fine as long as you never need to swap the barrel or barrel nut.
I tried FedEx and UPS earlier this year. Neither would send it. (UPS said they would if I had my own UPS account.) I ended up using SpotrsWorld. Their rates were decent, relatively speaking.