I personally believe Budgies thrive with budgie companions. Male pairs tend to do very well together. As for being territorial, as long as you take introductions slowly and have a large enough cage that they can each have their own space, there shouldn't be any issues. When you're ready to house them in the same cage together, it's a good idea to rearrange the toys and perches so that the cage feels new to both birds. Also a good idea to ensure each bird has it's own food and water dish and if they fight over toys then maybe have 2 of the same toys in the cage so each birdie has it's own. I also recommend getting a baby as a new companion as it'll likely make the bonding process much easier for you. Just ensure you have a back up plan in case the two budgies absolutely can't get along. Hope all goes well!