Mass fabricator, (you may have to enable it in the gregtech config), you'll need a fair amount of EU/t and scrap to get it at any appreciable rate.
You can also mine it, though you won't find much without a dense ore world from mystcraft.
You can also use the gregtech matterfabricator if you already have enough iridium, chrome and titanium to make one, though it uses a LOT more energy than the mass fab by default and HAS to have scrap unless you have tweaked the config.