Well that would be the ISB then Cale. They are not part of the military and answerable only to moffs and high command. Because of that and the authority given to them they can assume command of a military role like the lt. Col. You mentioned.

And yeah I can help s co-gm.  And I know of 2 planets that match your criteria. There is Roon. It is an old sith fortress world. It would be chalk full of relics of interest to the empire. There is also Kesh. It was home to the lost tribe of sith. That could be the resource the empire desires.