If you want an ultra-gloss look with a hint of metallic that approximates Ilfochrome your best bet is probably the Pictorico PPF150 Pro Hi-Gloss White Film, but that prints much better with a dye printer than a pigment printer though it might print well if your printer has a gloss optimizer. But it is the definition of a "bright polyester base".
That's so strange, before you posted, I was in Adorama, and ended up buying just what you suggested: Pictorico Pro Hi-Gloss, on the same basis - ultra glossy nearest thing to Fujiflex/ Glossy Ciba's.
My printer doesn't have a gloss optimizer, and it's pigment, so, the problem has been the printed areas get significantly duller than the native untouched paper. Like you mention, I think it would be better with Dye printers, than pigment, but I don't use those.
The Pictorico is chock full of OBA's - off the charts, but it will do for this experiment. It profiles fine too, as its not really a 'metallic'.
I guess what I'm looking for is ultra glossy with just a hint of that metallic/pearlescent sheen that the Fuji's & Ciba's had. The new deeply metallic papers that are out there now are really a new inkjet development (Like Moab's Silver Metallic etc). Those are amazing products, but not the Cibachrome imitators I'm seeking for this work.