Let's start with Inverness, it's a habitable planet within arms reach of supply-lines from the IMG and Bretonia. I doubt the locals would be to happy with our presence but I believe our equipment and the skill of our pilots would be more than a match for them. We could perhaps come up with a deal with the Bretonians in settling refugees elsewhere on Forres.
Sigma-21 and 59 are closer to our current AOE while leaving us far from a reliable supply route. We would be in a nest of enemies unless we could get buddy-buddy with the GMG.
Kansas in my honest opinion is a death wish. With our current plans we have against the Legion and our proximity to Liberty. I cannot stress this enough our logistics WILL be cut off with the Legion at our back and the Gauls and Liberty to our front and do not get me started on Turtle Creek.