You will most probably to make them yourself by using a image manipulation program such as Gimp (Free) or Photoshop (Not so free). Check the card resources in Pokebeach's fake creations to get an basic ideas.
Most probably for the HGSS fakes you will need few fonts :-
Gill Sans Font Set
Futura Font Set
Frutiger Font Set (not sure about this)
Sanvito Pro