The way I understand it, the Glock 18 was first introduced in 1986, same year as the ban on registering new full-auto guns. There might be a couple of transferable Glock 18's out there... I'm not sure of that, but that's the rumor. Good luck finding one, and it'd take a truckload of money to buy one if you did.
I think the FA Glock in the original video, with the drum mag, is a converted Glock 17. See the little dohickey on the rear of the slide? A true Glock 18 was only identifyable by the '18' marking on the slide, and an oddly out of place selector that looks remarkably like a safety lever on the rear of the slide.
The one I was shooting belongs to John Ross, it's a true G18, but I seem to remember him saying that it wasn't transferable.
**Edit: Oops, I checked the member list, JR isn't on here. Must have been thinking of a different board. Sorry