Last night I Ran Whisper, Sigma OGP. I loved my Whisper and OGP build but the Simga was just ok. So I figured I would essentially just copy my OGP which leads to this list:

"Whisper"/TIE Phantom (32)
Sensor Jammer (4)
Veteran Instincts (1)
Advanced Cloaking Device (4)

Omicron Group Pilot/Lambda-Class Shuttle (21)
Ion Cannon (3)
Tactician (2)
Rebel Captive (3)

Omicron Group Pilot/Lambda-Class Shuttle (21)
Ion Cannon (3)
Tactician (2)
Mara Jade (3)

Replace Mara Jade with something else until she's available.

When I played with the captive shuttle it put out a lot of stress, denied a fair amount of action, and was enough of a presence to give my Phantoms some room to zig and zag.

Ion Cannon with Tactician is a fun(annoying) combo.

I like the idea of

Whisper +VI+ advance cloak

Omicron group x3

I call it Cow "Whisper"er

Replace mara jade with darth vader (until it's released) and you still have a great list with a doomshuttle in it.