To be honest I think Tau work better in terms of the variance in alien species however I'm not familiar Eldar rules so I could be wrong.
I'm guessing you're planning some rather heavy converting in order to accurately represent the Covenant?
For the sake of simplicity I'll lay out a similar list to yours as to what I think would be a good match.
Units: Arbiter - Aun'Shi/Shadowsun
Prophet of Truth - Aun'va (With Council Honor Guard Elites as bodyguards)
Prophet - Etherial
Elite - Stealthsuit
Grunt - Firewarrior
Spec. ops Grunt - Pathfinder (?)
Jackal - Kroot (I'm not sure how you could represent the jackals with shields though)
Brute - Krootox (eupiped with bruteshot and appearing to lead a group of jackals such as in Halo 2 and 3)
Drones - Vespid
Hunter - Broadside
Vehicles: Scarab - Riptide
Ghost - Piranha
Banshee - Razorshark Strike fighters
Wraith - Hammerhead Gunship
There is some wargear that will be difficult to represent since there isn't really a Covenant equivalent but that's where you get to be imaginative and a bit creative so as to come up with your own representation

Also there are some units (Pathfinders) that may potentially represent one or two different Covie units (grunts/jackles)
I hope this helps you out and isn't just making it harder to decide between Tau and Eldar
Good luck