The crate training for 2-3 months is a good time frame to start with. Use the crate when you can't be home but make sure the pup is taken outside every couple hours. The time can be slowly increased that they stay in the crate. I don't think any pup/dog should be kept in the crate for a whole work day. Get a friend or family to stop by every day to take them out or hire a service who can do this.
As for when they can be allowed the run of the place, it all depends on the dogs. Some are never a problem. Others die of old age.
Since you have the breed narrowed down, start with breed specific organizations/associations. AKC is helpful but not always the best. http://www.gundogbreeders.com/ is a good resource for a gun dog breed. Puppyfinder is not a good place to shop. Hip and CERF is a must IMO.
Dew claws are debatable as well. Tight fitting dew claws are very very rarely ever a problem. I wouldn't worry about dew claws.