Sorry to hear of your father, and the troubled times you've gone through.
Your father will always be with you, living through memories and photographs like the one you show. Photography can be so important, and to me those portraits are some of the most important photographs we can make.
From my own experience, my strongest work has always come in times of turmoil and pain, or even extreme happiness. My creative juices don't flow very well when life is easy and I actually have time to do something with it. Use the feelings you have within to strengthen your work, and it may even be therapeutic to work on your emotions by thinking about them and channeling them in your work.
Hope you can get that darkroom up and running soon. I agree with the approach of starting with the finished product and what you want to achieve, and based on that decide which equipment to use. The camera is, to me, the least important piece of the puzzle, so long as it is reliable.
Best of luck to you, Matti!