To clarify, if the manufactured/mobile home has been attached to a permanent foundation, which means that the wheels and towing hitch have been removed, then chances are you can get a low fixed rate FHA loan. As Suzanne said, mobile home lenders will charge much higher interest rates than an FHA lender would. So the best option would be to see if the home is HUD compliant first. Manufactured/mobile homes are an affordable and suitable option for many borrowers. In fact, the newer models are virtually indistinguishable from stick built housing.
These homes are not registered with HUD, the outside tag on the home certifies that the home was built in accordance to the Federal "Manufactured Housing Construction and Safety Standards", which is a requirement for HUD financing. Prior to June 15, 1976, these standards were not in place. If the home has tags and an interior data plate, then it is a manufactured home. The interior data plate is usually in a linen closet, inside of a kitchen cabinet or by the electrical panel. This will give you all of the details of the home, such as wind zone, roof load, heating, cooling, manufacturer and model #.
Also, you can check with the local tax assessor's office to see if this home has been classified as real property. If you need any help, please feel free to contact me.