I've confirmed the Kodak Metallic papers I saw are the wet print ones, not inkjet.
For that transparent, glassy look, it seems I could go through adoramapix. It's about $15 per 20x20, not bad.
It's a big relief that I don't have to put much thought on this to choose the ink jet printer.
R3880 still the choice, in general, for ink jet?
I'm still splitting between
-- R2000 (13x19 or 13x44, with roll supported)
-- R3000 (13x19 or 13x44, roll supported), and)
-- R3880 (80mm tank, 17x22, no roll support)
Any objection?