You'll find most mid-range to high-end inkjet multifunction and most laser multifunctions will provide this ability, particularly those that have a dedicated Scan function button and an Ethernet/Wi-Fi connection. Most will be able to scan to PDF and JPEG, though Bitmap is a bit of a trickier one. Without knowing what else you need in the multifunction it would be a bit hard to find a perfect printer for your needs, but to start you off have a look at HP's Officejet Pro 8500 Wireless.

Try checking out for more information about the NeatDesk Desktop Scanner and Digital Filing System. Besides being able to meet the needs you mentioned, it can do a lot of other cool functions like being able to scan both sides in color and fast, combining several pages into a single document. The adf consists of three partitions allowing you to auto-scan several documents of varying sizes.

In case you need to work through a network, check also the same site's page on network document scanner, featuring the HP SCANJET 7650N and the Fujitsu FI-6000NS.

Otherwise, there's always google to help you find more information. :)