Increasingly A4 and even A3 scanners have a small enough footprint to be called desktop. The main things to look for in these scanners are the page per minute speeds and the amount of documents that can be loaded into the feeder.
Our favourite two production scanners are the A3 Panasonic KVS-4065 for unbeatable pricing and the Ngenuity from BBH (Kodak) for reliability and speed.
Panasonic KVS-4065
BBH Ngenuity
All the major brands have Desktop scanners. Please click on the logo ofyour chosen manufacturer below to go to their individual pages.