As Dragonfish mentions, it seems you could be better served by a parafoil kite. No tubes and spars, and they can be folded or stuffed into a small bag. If you encounter people who would destroy your kites, a dual line kite if you're looking for activity would probably be better as it's easier (and less costly) to replace two lines rather than four.
For ready-made kites, an HQ Symphony, Prism Synapse, Skydog First Foil, Cross Kites Air or Boarder, or maybe smaller with a Flying Wings Mighty Bug, and many store-specific variations which may have better availability in Brazil. They fold down small in a backpack, are lightweight, and are difficult to damage in a crash. They can still have lines cut or other damage by aggressive fliers, so you'll need to stay away from destructive people.
If you're looking for more pull, HQ Rush, Prism Tantrum, or even a Prism Tensor or Elliot's Magma may be more your preference.There are many variations and store brands of these, as well, called power kites, traction kites, and trainer kites, they can produce tremendous pull if you're feeling vigorous or are in need of a demanding workout, or are considering kiteboarding, kitesurfing, or riding around on a kite-powered buggy. Larger designs really should be only flown over water due to the ability to lift people into the air, and those landings are harsh. Beware with these larger kites, they require more training and safety mindfulness as they increase in power.
That is an option. Do you want to spend your days flying kites, or designing kites?
Or if you have your heart set on a smaller frame kites, some kites have "travel frames" available.
Rev 1.5 travel frames are about 40 cm long. If that works for you, many of the revolution 1.5 sized kites (Rev, Djinn, Phoenix, RevoPolo, etc) could work with modification if they don't sell travel frames. Basically the rods are cut in half, although it does affect the strength and flexibility. You could do the same with a dual line framed kite, although each joint introduces a weakness and changes how the frame flexes and bends.