The FM Argentine Hi Powers were all steel, and all based on the late Classic design. There are two versions of the FM, the earlier one (more desirable IMO) like this, with the correct slide cuts which were made under license from FN, and the later version that didn't have the scallops on the front of the slide that were produced after the license ran out, but Argentina kept making them. All the parts are interchangeable.
Leaving aside the alloy framed FN, any of the Hi Powers are good to go for lots of shooting. The Mk II and MK III had some minor differences that make them more user friendly, but they are all pretty robust.
The early internal extractor version of the Classic can be hard to find the extractor if it breaks, but there are some parts out there.