You are very smart to take up training classes with these dogs. Raising and training one young dog is a lot of work, you are taking on two! You've got literally years of training ahead of you. These dogs will be pup's until they are about 2 years old. Fortify your coop as much as you can, don't be afraid to put a hot wire around it! That's what I use to keep dogs away from my pens and it works. No dog, not mine nor neighbor dogs, have ever touched that wire more then once. I'd rather have a dog get zapped and learn to keep the heck away then to have my birds slaughtered.
Just keep one thing in mind for quite a while: Your dogs are young, high energy pups with a lot of interest in those chicks. Don't ever trust them alone with them, or with any kind of access to them for a LONG time! Keep in mind too that, no matter what anybody says, not EVERY dog can be trained to be trustworthy around chickens, not every dog has the right temperment. You just have to keep up your training, let them mature, and see how they do. Good luck, your on the right track.