I've got an SC coming up and I'm considering 2 lists, though I haven't decided yet.

I've recently bought an Gozanti and got a Decimator for my birthday.

So here's the lists:

"Whisper" — TIE Phantom 32
Veteran Instincts 1
Fire-Control System 2
Agent Kallus 2
Advanced Cloaking Device 4
Ship Total: 41

"Wampa" — TIE Fighter 14
Ship Total: 14

"Omega Leader" — TIE/fo Fighter 21
Juke 2
Comm Relay 3
Ship Total: 26

"Howlrunner" — TIE Fighter 18
Ship Total: 18

List 2:

Rear Admiral Chiraneau — VT-49 Decimator 46
Veteran Instincts 1
Ysanne Isard 4
Rebel Captive 3
Engine Upgrade 4
Ship Total: 58

"Whisper" — TIE Phantom 32
Veteran Instincts 1
Fire-Control System 2
Agent Kallus 2
Advanced Cloaking Device 4
Ship Total: 41

Not sure if Kallus is better on Whisper or get Moff Jarrod on the Decimator instead.

Kallus is best against low enemy ship counts (like 2/3 ship builds). If you see that a lot, then Kallus makes sense. If your meta consists of mostly 4+ ship builds, then Kallus is less useful.

Having said that, either of your builds are fine as is.