Yes, you can go anywhere, and use any
12v panel.
Before deciding on a system, I suggest reading up on the subject first.
The Fit RV's "How Much Solar Do I Need" blog post and
AM Solar's "RV Solar Education" are a good start. They'll give you a good understanding of what goes into a solar system, whether solar is even right for you, and how much you might need.
If you haven't done much camping yet in your unit, I'd suggest you do as much as possible before investing in too many upgrades. That'll give you a better idea of how you want to use your Airstream, and what the right upgrades will be.