I have played the games and here is generally what you would want to make.
Alliance
Normandy
Fighter
capital ship
Turian
Fighter
Capital ship
Frigate
Asari
Destiny Ascension
Collectors
Ship
Base
Fighter(has a name will find it)
Geth
You got all of those
Cerberus is also covered
Also the Quarian fleet. There capital ship the only major one
There is two types of reapers and harbinger is a larger version
The citadel is THE space station in the game, Omega as well.
I think that covers all major ships. There are a host of smaller ones as well of course but they are mostly non-essential. The list I made also includes ships you wouldn't need but are pretty cool. The list you have suffices but it would be better if you added the asari ship. Beyond that the rest I mentioned are nice but unnecessary ships.
To Mankind
And the hope that the war against folly may someday be won, after all
Isaac Asimov