The last collar I bought was 12 years ago, and I know technology has changed a bunch since then. What are you guys using? Is there a controller that will control 2 collars? It's going to be used on my current springer pup and the next one we are looking getting.

Dogtra 2300ncp for training. 2 dog training with one controller with quick level change knob.  has a nic and separate continuous button.  Garmin makes a good track and train with multiple collars and hand held gps with boundary alerts and all kinds of features that I use also.  Works up to i think 9 miles. I have brought my dogs back at about 500 yards but I have a Mal and a GSD so not hunt training.

I need a collar or two for training. 3 year old dog who likes to bolt through open door/gate/anything and run off for hours. 5 month old GSD who will need it for training as well.

The dogtra 2300 ncp will work good for the 3 yr old and the GSD pup but it take some time with them working for the training to stick.  I have seen very over reactive and undisciplined dogs under control in just a few minutes but it takes ongoing training and time with them for it to stick.