Quite oddly, I'm on CivFanatics for years but I seldom posted anything in here. I'm actually more active on Wikipedia (all those articles about Pedro I, Pedro II, Empire of Brazil, etc... were written by me).
I'm glad to see Brazil as a playable civilization on the game. It was about time in my opinion. However, if you don't mind, I'd like to make a few comments regarding Brazilian UUs:
Bandeirante (roughly "Flag-bearer"): Brazil did not expanded its territory in the colonial period because of the Bandeirantes. In fact, Portuguese America was then divided in the State of Maranhão (present-day states of Amazonas, Pará, Maranhão and Piauí) and the State of Brazil (everything else down to Sacramento (in present-day Uruguay). The inhabitants of Portuguese America did not regard themselves "Brazilians". They saw themselves as Portuguese, subjects of the Portuguese king. Although the Bandeirantes (Flag-bearers) are unique to Brazil's history (and not to Portugal), they belong to na era when Brazil did not exist as a nation. The Bandeirantes were Portuguese-born, Indian and Mixed-blood (sons of Indians and Portuguese) explorers, Indian slavers, mercenaries and gold searchers. They did not create settlements. Settlements, which led to Portuguese America's territorial expansion, were created by Portuguese troops (there are still many remnants of Portuguese fortresses across Brazil that eventually evolved into settlements and finally into towns).
Imperial Guarda de Honra (Imperial Guard of Honor): The cavalry Guards dressed in white and gold helmets were created in 1822 and existed until 1831. They are known nowadays incorrectly as "Dragões da Independência" (Independence Dragoons). They were not dragoons, but cavalrymen and they had no part in Brazil's Independence. When the painter Pedro Américo painted the famous "Shout of the Ipiranga" which depicts the then-Prince Dom Pedro (later Emperor Dom Pedro I) declaring Brazil's Independence on 7 September 1822, he dressed Pedro's entourage with the later Guard of Honor's uniforms, even though they had not been created yet. It was a mistake caused by Pedro Américo: the Prince was followed by a guard of honor (some were military officers, others were civilians, all were volunteers to accompany Pedro during his trip in the province of São Paulo), but not the Imperial Guard of Honor which was created in late 1822.
Batalhão do Imperador (Emperor's Battalion): this was the infantry equivalent to the cavalry Imperial Guard of Honor. The celebrated Duke of Caxias (back when he was young and decades before he became a titled nobleman) was part of it. The Emperor's Battalion fought in the War of Independence (in the province of Bahia) and later in the Cisplatine War. It was disbanded along with the Imperial Guard of Honor in 1831. Since both betrayed the Emperor, they were regarded a threat by the government after Pedro I abdicated. (the future Duke of Caxias was na exception: he remained loyal to Pedro I to the very end)
Voluntário da Pátria (Fatherland Volunteer): the Fatherland Volunteers were created in early 1865. Every civilian who volunteered or was conscripted to fight the Paraguayans in the Paraguayan War became a Fatherland Volunteer. They came from all over Brazil. They were ordinary citizens, with no military training. Five years of brutal warfare turned them into highly experienced, battle-hardened men, equiped with state-of-the-art weapons.
Cangaceiro: they were outlaws, bandits, criminals who raped women, castrated men and robbed and ransacked towns. I feel insulted when I see a few people on this forum suggesting these brutal criminals as possible UUs of Brazil. I only mentioned the cangaceiros to make clear that we should stop talking about them. It's really offensive. It's like proposing serial killers as USA's UUs. Disgusting.
Final verdict: the Fatherland Volunteers. Brazilians from every province became Fatherland Volunteers. They are the only truly national unit that could represent Brazil and all Brazilians.