Sorry....missed the question about replicas......Paiste re-introduced the Giant Beats after being discontinued for many years back in 2005. They're not exactly like the originals, but they are close. Nick later went on to 2002s and then later Signatures....so it all depends on what era of Nick's cymbals you are trying to replicate or capture.
I've got to tell you though, that you can get pretty close with mixing the current Zildian A customs and certain K custom models too.......they shimmer just as much and are not quite as harsh sounding as some of the Paiste's are....but....if you must replicate Nick's setup to the T he used Paiste......just remember, you'll only come close....why? You're not Nick Mason, or Bonham, or whatever famous drummer's sound you are trying to achieve (and neither am I!! LOL!!)....you are you first and fourmost and that will always shine through first. What I'm saying is.....look for YOUR sound....be yourself and not always try to be like: insert name here.