bigalc

You can absolutely take your dog to a trainer. If you don't have a good bit of hunting experience this might be the way to go. And no, the dog would not have to be purebred. Actually, for a multi-purpose dog a mixed-breed might be preferred. If the trainer acts like a snob about training a mutt, then hang up the phone. It's your money after all.

Taking a dog to a trainer brings up a whole set of other concerns though. For one thing most trainers will only train on one type of game. So if you want a multi-purpose dog you would have to go to multiple trainers.
If you take your dog to a trainer make sure to ask for references first, and then call every one of them. Ask lots of questions.
When you talk to the trainer ask lots of questions as well. Ask what happens if your dogs gets sick or hurt, or if it dies. Ask what type of food he feeds. Ask if you can come to observe during training. Ask what age he prefers the dogs to be when they start training.