well, this question is easily solved since the porky should be in a 75g MINIMUM or more, i would say no. And they're not invert compatible. This isn't true for EVERY puffer, though. There is ALWAYS and exception to every rule. Also, because your tank is so small, and the puffer gets rather large, the puffer's territory is going to be much bigger, and therefore, it will act more aggressively toward other fish. It's territory may very well take up a good portion of your tank, so IMO, it's not a good idea. Sorry to be a bubble buster, but there are plenty of other awesome fish for your scenario.
here's some info:
Minimum Tank Size: 90 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 1' 6"
Color Form: Black, Gray, Tan
Temperament: Semi-aggressive
Reef Compatible: No
Diet: Omnivore
Compatibility: View Chart
Origin: Caribbean
Family: Diodontidae
The Porcupine Puffer is also known as the Porcupinefish or Porcupine Pufferfish. It has spiny appendages which cover most of its body, which may vary from light gray to mottled tans, sometimes with dark spots. Its teeth are actually a fused beak-like structure. The Porcupine Puffer lacks pelvic fins but has learned to use the pectoral fins to move about.
A 90 gallon or larger, fish-only aquarium with a good protein skimmer is a suitable home. It may be aggressive at times, nipping the fins of tank mates and leaving a circular hole as its mark. It will eat invertebrates found in a reef aquarium. It has the ability, when threatened or scared, to inflate its body to almost twice its normal size. Parts of its flesh are poisonous if digested.
The Porcupine Puffer needs a varied diet of meaty foods including; squid, krill, clams, and hard shelled shrimp to help wear down their ever growing teeth.
hope this helps!!!