I was in the middle of reply when my "&^$%-^$#" dial up crapped out on me and then I had to run to the store.
Bolth of the boxfish I looked up and on the site I found said they need 125 gallons min. And when stressed can release toxins and kill all the other fish in the tank.
As for puffers
1. This one needs 70 gallons
Minimum Tank Size: 70 gallons
Care Level: Difficult
Tank Conditions: 72-78°F; sg 1.020-1.025; pH 8.1-8.4; dKH 8-12
Max. Size In Aquarium: Up to 10"
Color Form: Black, Tan, Yellow
Temperament: Semi-aggressive
Reef Compatible: No
Diet: Carnivore
All of these need 50 gallons
2.Blue Dot Puffer
3.Honeycomb Puffer
4.Saddle Puffer
5.Saddle Valentini Puffer
Minimum Tank Size: 50 gallons
Care Level: Moderate
Tank Conditions: 72-78°F; sg 1.020-1.025; pH 8.1-8.4; dKH 8-12
Max. Size In Aquarium: Up to 5"
Color Form: Blue, Deep Blue
Temperament: Semi-aggressive
Reef Compatible: No
Diet: Omnivore
This one needs 30 gallons
6.Saddle Valentini Puffer
Minimum Tank Size: 30 gallons
Care Level: Moderate
Tank Conditions: 72-78°F; sg 1.020-1.025; pH 8.1-8.4; dKH 8-12
Max. Size In Aquarium: Up to 4"
Color Form: Black, Blue, Brown, Orange, Yellow
Temperament: Semi-aggressive
Reef Compatible: No
Diet: Omnivore
There are other puffers but they need 90 gallons or more. As you can see all of these are not reef safe sorry but I am sure someone may come up with one you can put in there.