I would vote against the fox face. Most can probably get too big for that size tank.
I might also disagree with the long nose hawk. They are cool fish, but I dunno if I would label them active swimmers. At least not the ones I saw.
If I would weigh in on this I would say:
Damsels are great active fish if you can get past the attitude.
Black cap basslets, and most basslets in general are active fish.
There are some specific species of box fish that are small enough to live in a 45 and usually boxies are active.
Fuzzy dwarf lions are full of personality.
Puffers are always fun. Saddle Valentinis are small enough for a 45g. As well as a few others.