Introducing new budgie

Hello! I've had two budgies for about 5 years now and recently one passed from cancer. Now (after a week or so of grieving) I'm in the process of adopting another ≈5 year old male budgie for my surviving (also 5 and male) budgie.

I have a few general ideas for how I want to introduce them, but I figure it's always good to get some second opinions, so please tell me if there's anything I'm missing!:

- Quarantine period where they're in separate rooms

- Week or two of them being in the same room but in different cages that slowly get closer; flying time is one at a time

- Supervised short but slowly getting longer periods where they're out at the same time with treat rewards when they're good

- Rinse and repeat supervised time together until they can be out together but in separate cages at night

- Eventually trust them to sleep in the same cage?

My current bird is relatively shy but can be territorial over food occasionally (he and my deceased bird always had 2 separate food/water bowls so this would continue) so I want to make sure I can do the best I can for him and his future friend. Thanks in advance!