Definitely adopt and do it from your shelter. And get a mutt because they tend to be smarter and healthier. Don’t go to a shelter looking for a breed, go to a shelter looking for a dog that you make a personal connection with. That is how I have always done it (with one exception that we got from a rescue instead) and I have not regretted it with the four dogs I have had in my life.
I am sorry you had to lose one of your dogs. It’s always so hard because to a loving pet owner, they are family.