happy birthday to your dad!
try asking at your favorite grocery store. This type of cake is usually found at the bakery counter of big grocery stores.
another option would be to see if the store would print your picture on a piece of white or dark chocolate (depending on what you like) and you could order a cake from a good place then put the picture on top of it. that way at least the cake would be edible and won't have the horrible tasting grocery store icing.