As for the other species of Epaulettes.
While the most commonly found is the Common or Ocellated Epaulette (Hemiscyllium ocellatum).
There is also the Papuan Or PNG Epaulette (H. hallstromi) - which maxs out at about 30-32", and can occasionally be found.
The Speckled Epaulette (H. trispeculare) -also maxs out at about 32". It tends to be pretty rare - but can sometimes be found.
The other species tend to be very hard to find.
Still considering that Epaulettes tend to be known as "Walking Sharks" - a pond with an 8 foot diameter could still be enough for a single 42" Ocellated Epaulette or a small breeding group of PNG or Speckled Eppies.