Is much of the problem about differing varieties of Portuguese? Last I heard the Portuguese language Wikipedia allowed multiple versions of Portuguese in a similar way to English - i.e. standardised at the article level not the project level; Though the editing base is much more skewed to Brazil than EN is to the US. Assuming Angolan Portuguese is closer to the Portuguese spoken in Portugal, then just as in EN you are likely to get some goodfaith newbies "correcting" spelling to the version they know. If so perhaps edit filters might work. Alternatively, would it be possible to do something similar to the Chinese Wikipedia and display different versions of Portuguese according to user preference/IP geography?
WereSpielChequers