Aside from the offensive bonus of ramming, to me, part of Oicunn's "defense" is having him base targets as often as possible - if they remain based, they won't be able to shoot at him. With that in mind, Navigator, Expert Handling and Engine Upgrade each offer nice benefits when it comes to positioning.

Captain Oicunn (42)

Expert Handling (3)

Navigator (3)

Ysanne Isard (4)

Rebel Captive (3) / Mara Jade (3)

Engine Upgrade (4)

That leaves you with 41 points for a variety of reasonably loaded aces, for example:

Whisper (32)

Veteran Instincts (1)

Advanced Cloaking Device (4)

Fire Control System (2)

Tactician (2)

(Or, in place of FCS & Tactician, Sensor Jammer (4))