IIRC there was a thread discussing this board a while ago (aha, found it:
http://geekhack.org/index.php?topic=47024.0). There was a claim that they have a metallic coating, but they're plain old ABS underneath and coated with polyurethane, which is not that durable (UV cured silkscreened polyurethane, I suspect there is no actual metal involved). The ones you linked to are actually zinc metal (kirsite) caps with gold colour and laser etched legends, but they also have some sort of plastic coating which eventually wears off and then they can start to look rather poor. They won't feel the same.
If you want caps that feel the same, try to find some other PU coated caps. They feel nice for a little while, but then the coating wears off... And then you just have some thin ABS keycaps that don't feel nice.
Better to get some nice thick, high quality caps that will continue to feel nice for years and years.
As for material, if you like slick feeling caps, try POM. If you prefer a "dry" feeling, try PBT. ABS wears fairly quickly and when smooth can be "grippy". That said, high quality thick keycaps are nice in any material.
For example, GMK doubleshot ABS caps, IMSTO thick dyesub PBT or Cherry corporation thick POM originals are all fantastic feeling caps. Despite being lasered, the POM caps are my favourite, though.
