There were three different stock pans '70-'75 and all the changes were inside. Pan 1 was an empty bucket with nothing inside. Pan 2 had a horizontal baffle inside about 2" off the sump bottom; the stock circular pickup reached thru a hole in it. The Boss 351 pan (#3) had that plus a rudimentary crank scraper on the sloping part above the sump. They are all useless on a hard driven Pantera.
Hall and others used to sell a drag race pan with a deep sump and no baffles. That also won't save your engine in hard cornering or track driving. T-pans for a Mustang won't fit between the frame rails. The Gr-3 pan dwg shows a stock-appearing (6 qt?) pan with an anti-reversion shield mounted to the main caps. I've never seen a post-'80s wide-body pan but the early pans fit so I suspect DeTomaso used one of the three listed above.
You should look for one of the 10-qt fully baffled aftermarket pans you listed. I've not seen one available used in quite awhile but they ARE worth the price as-new and all the vendors have them on the shelf. Aviaid also has the same pan for the 351-W which is also vulnerable to losing bearings in a Pantera.