I collect the old Manley popcorn machines. They are a fun project to restore. In terms of size, the one on American Restoration was a Manley Premier model. It is approximately 30" wide by 20" deep and a little over 5' tall. This is one of the smaller machines. There are some counter top models as well that are smaller. The advantage of the Premier is that it runs on 110 volts. This model is on casters and is easy to move.
Many of the machines are of the larger size, such as the M-Line and Aristocrat. These machines are approximately 36" wide by 24" deep by 6' tall. All of the cabinet style machines are on casters and can be moved fairly easily. The M-Line and Aristocrat are heavy and you would want to avoid steps unless you have plenty of help. Most of these machine run on a 220 volt circuit. The M-Line and Aristocrat are two of the more popular models as these are the machines that you saw in the movie theaters in the late 1940s and 1950s.
These machines make the best popcorn. If you tried my popcorn, you would never eat micorwave popcorn again. These machines were designed to make great popcorn. They are better than the vast majority of popcorn machines made today.
The other thing to consider is that these machines are relatively inexpensive. You can generally find a good restorable machine in the $400-$500 range.
If you have any questions, just ask. I run the Manley Popcorn Machine web site. Please feel free to stop by:
http://manleypopcornmachine.com/