From the Warman site, "Concealed beneath the case are two coils wrapped around carbon steel blades with a powerful ceramic magnet". So the Firebuckers are a blade-style humbucker and not of 'true' Firebird construction. I'd imagine they'd probably sound quite similar to your Firebucker II pickups.
The trem 'ceramic magnet' conceals a whole range of different formula magnets. Unlike alnico, which has the numbering system (which itself has irregularities and only gets you to a rough ball-park area), I'd imagine there are so many different compositions of ceramic/ferrite magnet that a numbering system would be too complicated, so you'd have to go right back to the manufacturer's magnetic property tables for that particular type of magnet. But it's rare you'll ever see those as an end-user. And you normally don't need to know either. "High-quality' is just marketing speak IMO. The qualities you want are dependent upon the application, so what may be a good magnet for one job is inappropriate for another. But the magnet quality is the same.