Somebody already said my suggestion- wait until you get the dog and let a name pop up. I've done that with all but two of the pups I've bought and they all seem to have worked out well. Just remember, the call name and the registered name do not have to be the same so if you are under any time constraints regarding registering the pup, you can send in one name for the papers and another one for in the field.
One can also do this with an older dog if you don't like its call name. Switch to the new name as if a puppy and he will quickly catch on. I've done that on many older dogs when their name did not fit their personality. Or when the call name was not appropriate for public use.
