I would actually only use Dark eldar for their models and model parts, as far as we know eldar corsair are craftworld based, if you start looking at some FW books, you'll start finding quite a lot of fluff and even proper corsair units.
A corsair prince for example is pretty much the same as na autarch, normal warriors are guardians, rangers are also commonly seen amoungst Corsair forces.
Corsairs obviously love aircrafts, pretty much every eldar flyer can be used in a corsair army, most non aspect warrior stuff can be seen as cosair stuff. There are no temples on corsair ships, but it's not completely out of the question to think they have no aspect warriors at all, this is a blurry area however.
FW announced they will be releasing some new eldar units and new eldar fluff in a future Imperial Armour, including corsair and exodite units.
Modelwise eldar with some dark eldar parts are the best way to represent a corsair army.