Where in Portugal do you live? Do you have a slope near you? A glider like the one you have seen will work pretty well on most, or, if you want hi-start it from a flat field. I have flown full-size along the Atlantic coast of your country in an old Fournier motor glider witha VW motor! Very cheap as the wind from the sea gave excellent lift on the cliffs/dunes between Lexios(?) and Villamoura. That was 25 years ago but I think the winds are much the same!