ambidextrous,
Only Spain has the requirement for a forestry/agricultural rating, Portugal does not.
But the funny thing about Spain is that, according to the local Air Regs (LNA-Ley de Navegación Aeronáutica), to be able to act as Pilot in Command of a Spanish-registered aircraft you MUST have european citizenship.
So, unless you already have this two requirements, Potugal would be your best bet.
Regards,
rcapiloto