I was wondering, what would the best phantom build be.
Phantoms
Which one?
Any build with tie phantoms
The standard loadouts are:
Whisper VI, FCS, ACD, 1-3 point crew of choice.
Echo VI, FCS, ACD, 1-2 point crew of choice
Sigma SPA, Intel Agent
The point ranges for crew described by @Keffisch are a little narrow; completely excludes Gunner. Gunner is a common crew upgrade for Phantoms, but not my personal preference. Otherise Keffisch nailed it: Veteran Instincts, Fire Control System and Advanced Cloaking Device are stapled to the TIE Phantom Aces.
I’ve seen some experimentation with Lightweight Frame on the generics, but I don’t recommend it for the aces.