A short focal length refractor would be a good choice.  There is the venerable standard Orion ST80, which is cloned under many names - the Meade AdventureScope 80, the Celestron Astromaster 80 AZ.  All of these are 80mm f/5 achromats, so they're about 16-20 inches long, including the dewshield.  

Shameless plug - at the store, we have too many of these (the Astromaster version).  They weren't selling at their regular price because we are selling the StarSense Explorer 80 for $10 cheaper, so we are selling them below what everyone else is selling them for to clear them out.  A bargain is to be had!  

The Astromaster comes on a nice stable, sturdy tripod, but it may not fold down small enough to easily fit into a carry-on.  Look into getting a nice camera tripod instead.  You'd probably be able to find a good used one for $100 or less.  

If you get a good Barlow, you can easily get up to some nice views at 100x in this scope.  Don't expect too much more than that unless you have some really short focal length eyepieces to Barlow, or a 2.5x or 3x Barlow. 

But that's not what the scope is designed for.  What this scope really excels at is widefield, low-magnification views, open clusters, sweeps of the sky, especially the Milky Way.  A humble 32mm Plossl will get you a field of view that is almost FOUR DEGREES wide.  That's practically binocular territory.  And, on a tripod, it'll be the best binocular view you've ever seen.  

I can personally recommend this scope; I have the Orion flavor, but they're all the same.  It is my goto (pun intended) scope for widefield views.