I like how you and your bf both voted yes
This thread would probably be more appropriate in the hunt suggestion thread.
Anyway, like Charlie said, it'd cost way too much to have multiple avis in one gender box, and adding the ability to choose which avi you get would completely sink ATA in terms of profit. In case you didn't know, they're a rather small group of people, so they don't have a lot of the manpower that would have to go into making this happen, not only from designing the avis but also recoding the boxes and these boxes specifically so you can pick which one you want, along with giving you both the male and female box.
Then, the reason the drop requirements for avi boxes is "high," is because the playerbase is growing immensely in terms of stats. The increase occurred just a short while ago, so the old requirement was around for quite a while. There are tons of larger players now that can easily score 35k+ drops every hunt. Making the hunt drops for the boxes lower would mean ATA would also be losing money (see above).