Almost all Pokemon servers are Brazilian dominated because that's just what the population consists of. There is not enough English speaking players to populate a server. Most people that play Pokemon servers are well.. Brazilians or non English speaking people.
PAdventures is an option, but it's been dying over the years and there isn't nearly as many people compared to like 5 years ago. Haven't played it in a long time so I can't say much for the English speaking community.
PokeXGames is probably your best bet for how well made of a server it is. There is also a decent amount of people that can speak English on there. I know that when I played, I always saw people talking in the English Chat. But most of the server is of course still Brazilian dominated.