So what it the most bloated, overweight and corpulent Decimator build you can come up with.
In terms of sheer hard-to-kill-ness I'm thinking along the lines of this:
Rear Admiral Chiraneau (59) VT-49 Decimator (46), Expose (4), Mercenary Copilot (2), Gunner (5), Dauntless (2)
I'm not certain about Expose and Gunner together - but if I'm going to make this a completely bloated build, then it can't hurt :-)