For more thorough information on sub species I.D you can check these pages out by Graham Taylor:
Head and Eyes Identification and Tail Feather Identification
Eclectus roratus roratus
Grand Eclectus
Ceram Eclectus, from central & southern Maluku, including Buru & Ceram Islands.
Average length 34 - 35cm.
Wing span 225 - 242mm
Eclectus roratus vosmaeri
Vosmaeri Eclectus
Halmahera Eclectus, from northern and central Maluku including Halmahera, Obi, Damar, Batjan, Mare, Morotai, Kayao islands.
Average length 37 - 38cm.
Wing span 210 - 261mm
Eclectus roratus westermani
Westerman's Eclectus
known only among aviary specimens
Eclectus roratus cornelia
Sumba Island Eclectus
Cornelia's Eclectus, from Sumba Islands
Average length 37 - 40cm.
Wing span 214 - 253mm
Eclectus roratus riedeli
Tanimbar Island Eclectus
Riedel's Eclectus, fromTanimbar Island in the lesser Sumba Island group near Aru Island
Average length 33 -34cm
Wing span 214 - 220mm
Eclectus roratus polychloros
Red Sided Eclectus
known in Australia as the New Guinea Eclectus, from mainland New Guinea, Wau Valley, Papuan Islands, Kai. It was introduced to Koror & some other smaller Islands.
Average length 35 - 38cm
Wing span 235 - 264mm
Eclectus roratus biak
Biak Eclectus
Biak Red Sided Eclectus, Biaki Eclectus, from Biak Island, Islands in the Geelvink Bay Normfor, Yapen, Mois Num
Avergae length 35cm
Wing span 215 - 242mm
Eclectus roratus aruensis
Aru Eclectus
Aru Red Sided Eclectus, Aruensis Eclectus, from Aru Islands
Average length 35 - 39cm
Wing span 247 - 270mm
Eclectus roratus macgillivrayi
Australian Eclectus
Australian Red Sided, Queensland Eclectus, Macgillivray's Eclectus, from Eastern Cape York Peninsula, from the Iron Range & Pascoe River, Mcllwraith Range
Average length 40 - 45cm
Wing Span 277 - 298mm
Eclectus roratus solomonensis
Solomon Island Eclectus
from Admiralty Islands, from Bismarck Archipelago, Lolobau, Wotam, Duke of York, New Ireland, New Hanford, Tabar, Lihir & Solomon Islands
Average length 33 - 35cm
Wing span 218 - 258mm