My 1GR-FE doesn't consume much oil, 1/4 of a quart in 5,000 miles, which is about what my 22R-E before used. I'm running 5W-30 Mobil1 synthetic. You will hear about the engine consuming excessive oil sometimes and it seems that certain brands and viscosities will cause it. Not sure there's any widespread issue so if it happens you need to change something, brand, weight, type, etc.
I don't know if it's difficult to service them in South America but I suspect that I'd rather have a 1GR-FE than something even newer. I'd have to think at this point having *some* technology in your engine is getting more common everywhere. Toyota stopped producing ultra simple mechanical diesels and carbureted gasoline engines a while ago now so VVTi and D-4D aren't as rare anymore.