At this point in time you probably won't be able to get non genuine as no one has them....and they can't cut/make you one up because the glass is curved ever so slightly (just enough to stuff ya)!!!
I know all of this after having to source two rear windows for my hardtop - there was no way I was paying the $1200 for genuine glass!!! I'm running tinted perspex windows now for a fraction of the cost - lighter, cheaper to replace and looks almost identical