Welcome to the forum Jennifer!
I'm going to go against the majority here. Why? Because I love the looks and the sounds of good vintage stereo gear. All my stuff except my home theatre gear is vintage, and to be honest, the home theatre gear sounds muddy compared to my good vintage gear. And it is upper mid stream gear too!
If I read correctly, you are looking at honouring your dad by getting back into vintage gear. There are lots to choose from, and most of what is still around sounds pretty good after a good deoxit treatment.
Some of my favourite receivers are early to mid 70s Kenwood and Sony. NAD is pretty good, but doesn't have that same vintage look. Early 70s Rotel is quite good, as is early 80s Harman Kardon. They will all give you that warm robust sound without breaking the bank like you would with vintage Sansui or Marantz. I also like early 70s Nikko.
I agree with others in that getting the right speaker/receiver combo is important. Especially when it is not top of the line gear. You want the right synergy between the two. Best to buy both from the same place at the same time so you can hear the synergy. I also agree that you can't go wrong connecting up with a local AKer. If you were in Ottawa, I would offer to help you, but I'm sure there are others around.
When testing out a receiver, if you hear crackly or static, or intermittent signal breaking up, that can often be fixed with spraying deoxit into the controls. It can even bring back dead channels, but no guarantees. Most larger cities have their share of experienced in vintage, techs. There are threads identifying them too. At least Canuck Audio Mart has one. Most fixes aren't too expensive, but if you want to restore a unit, expect to spend at least $250 for a basic restore job. More extensive will cost more, but you won't have to throw it away if it stops working. And that should give you another 30 years or more use out of it. You can't say that about most modern gear!