I would recommend for your situation the Rossi Puma (which i believe is a lever action) in .38 special and the revolver in 38 special. That way the ammunition is interchangeable between the firearms.

BUT depending on your firearms experience you may be better off with the 22 caliber firearms but I would worry about using 22s on the feral dogs and as self defense weapons.

The acquiring of ammunition is the biggest problem I can see in order to be proficient in the use of the firearms.

If it was at all possible I would recommend getting 4 firearms total the 22s for practice and small pest/snake control and the 38 special for self defense

Being that you are in Brazil I would recommend Taurus as a nice 22 revolver as I own a model 94 9 shot 22 from Taurus.

YMMV
Kirby