Great you're giving this some in depth thought. While a pet would be a great stress reliever, my concern would be how much stress the pup would be under.
What really caught my eye from your post was taking classes in dog training. I recently placed a pup with a trainer, one that works for Boone's Animals for Hollywood. Yep! my pup is filming a Disney Movie. But, that aside what a fantastic life this trainer leads. Hard work, but she is doing something she loves, working with animals.