Where can Signal Officers get stationed?

On active duty...pretty much anywhere. Reserve or Guard....where ever there happens to be a slot

Anywhere. Look at the profile of any Signal officer in RallyPoint and you will see a variety of assignments. If you have someplace you really want to go, make sure you keep your dream sheet updated.

Honestly anywhere.
Always a need for an S-6. Many Combat Teams have a Brigade Signal Company assigned.
They also have ESBs and different compositions of Signal Units and Teams.