I have about 7 days to spare in South America. Where should I go?

Hey fellow travellers!

Long story short, my wife and I are travelling to Brazil in March/April next year to visit some friends and family. We've already been to Brazil before, absolutely love the country, and plan on exploring different areas.

This time around however, we really feel like adding another country to the itinerary, and seeing a different side of South America.

Ideally, this is what I'm looking for:

→ Somewhere that won't make us feel like "we haven't even scratched the surface" after 7 days.

→ A country that might have a cool mix of culture/history/great food/safety

→ Ideally, something that won't break the bank, as we'll already spend a lot in Brazil.

→ Good weather around March/April.

Our ideas so far:

→ Colombia: We feel like we could maybe squeeze Bogotá/Medellín/Cartagena/Salento area within about a week. We are both coffee junkies, so the coffee region alone sounds really interesting.

→ Mexico: I know, technically not South America. We are considering CDMX & Oaxaca, though we might feel like we are missing a lot...

Are any of these great choices given our preferences? Do you have any other suggestions that might be even better for us?

Thank you!