I'd just stick to the Minolta kit and be done with it - as noted already, it's the more versatile of the two outfits. And a 24 is plenty wide for most situations you'll find yourself in, even if you're photographing in cathedrals. Where in South America are you going? I've been to Buenos Aires, Iguazu Falls in Argentina and Colonia, Uruguay. Even at Iguazu, you can't get a shot of the full span of the falls because it's broken up into sections, so I had no issues with having nothing wider than a 28. The people are worth investing some time photographing, so having those fast 58 and 85 lenses would be a really good idea.