I'm sure most of the shooting breeds would be able to be trained to track.
Spaniels would be best for it as they're more of a hunting dog, Labs are more of a retriever - although both breeds will cross over of course.
I think the key to any training is to build on the natural instinct of the dog, and make it fun.
My dogs know the difference between me doing my rounds, a pheasant shoot day and when I'm deer stalking. As you say they pick up on the owner and act accordingly.
Rhoda, a dog will be as unruley (or not) as the owner allows.
Have fun tracking with him.
The other thing is a dog gives you someone(thing) to share the joys of being outside with...
In a world whose only quarrel with instant gratification is that it takes too long, we are practitioners of a dying art: patience."