Hi Guys,
Most of the major manufacturers now use a combination of the roller shown in the earlier photo and a "separation pad" located somewhere beneath it. This is made from anything between rubber and cork and, when worn or dirty, is the usual reason you get a multi feed (Keep the covers on devices when not in use).
These rollers and pads are sometimes available as spare parts (service consumables) on the older machines and you should call a local dealer to find out if they can help. Often manufacturers do not stock them as many do not offer service for such small devices.
As for new devices here is some advice:
Ask yourself what you want to print most often and purchase a device capable of doing so using cartridges which are cheap (or can be refilled).
As mentioned the newer Bubble Jets can be cheaper than lasers these days and the quality is better some of the time (depending on model).
Most manufacturers will supply TCO figures (total cost of ownership) and this should be your main guide. pipper what it does! Most machines do about the same, cost about the same to buy but vary wildly in TCO.
If you need service, where can you find it? Be sure you dont get lumbered with a machine no one has spares for or cant fix! It has to be Canon or HP (actually the same if a laser as they are all made by Canon). If you buy something for the workshop do you buy an obscure Chinese brand because its cheaper? No, why not? Because the build etc is poor right? Its the same for printers!
If you need more advice drop me a PM as I could be here all day.
Kind regards,
Mick (Canon Europe NV)