Hello everyone.
I came across an Argentinian band named Metropolis who made a wondeful work in 2006, The Curse, and then almost disappeared despite they go on playing and composing.
I highly recommend them for the "prog metal" family. They show a good fusion of many prog themes, including some hints of Gentle Giant choirs.
The lineup is: Guitars: Emiliano Bracamonte - Keyboards: Diego Palma - Voice: Martin Puntonet - Drums: Daniel Márquez - Bass: Bruno Perine
Here are some samples of their music:
https://www.youtube.com/watch?v=0Aye8QOGTsU
https://www.youtube.com/watch?v=8YoLP1i2bBQ
https://www.youtube.com/watch?v=0u81URZdYeQ.
Waiting for a reply, I wish you all the best.