Zones for Portugal

Since I am implementing Dolibarr at the moment and that uses provinces and regions, I've been looking at the Portugal zones.

The zones in the plugin section uses 17 districts (although there are 18, Braga is missing) and the two autonomous regions.
ie:

Aveiro
Beja
Braga
Braganca
Castelo Branco
Coimbra
Evora
Faro
Guarda
Leiria
Lisboa
Portalegre
Porto
Santarem
Setubal
Viana Do Castelo
Vila Real
Viseu
Azores
Madeira

I have decided to go for the NUTS system using these zones:

Alto Minho
Cavado
Ave
Area Metropolitana do Porto
Alto Tamega
Douro
Terras de Tras-os-Montes
Tamega e Sousa
Algarve
Oeste
Regiao de Aveiro
Regiao de Coimbra
Regiao de Leiria
Viseu Dao-Lafoes
Beira Baixa
Medio Tejo
Beiras e Serra da Estrela
Area Metropolitana de Lisboa
Alentejo Litoral
Baixo Alentejo
Leziria do Tejo
Alto Alentejo
Alentejo Central
Regiao Autonoma dos Acores
Regiao Autonoma da Madeira

I would appreciate any comments from portugese natives regarding which may be more appropriate for people registering their address.
thanks
Steve
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