Well, first of all, I have to say Woooooo! on getting a new pup! Congrats!
In my experience, if Tink is a dominant female, you do probably want to go with a male. What would happen if the female pup you got also turned out to be dominant? That would not be a good match. However, even if a male were dominant, the two of them would mesh much better.
2 females can live together just fine, provided there is only 1 dominant dog b/t the two of them. I know some people who only have same sex dogs and have multiples and they get along fine (for the most part). But overall, male/female pairs tend to get along better and are more tolerant of one another.
Age difference can also play a part. Tink is still young and their ages won't be that far apart. Sometimes that can cause conflict b/t dogs vyying to be leader. The same goes if there were a huge age difference.
So it can be done with no problems. It just depends on your personal preference. If you want to get a female, it should work fine. Just make sure the new pup is not a dominant or alpha dog and there should be no problems.