Tyres we have used in South America (2010-2018):
Dunlop Grandtrek AT3 - good tyre on the highway, OK offroad
Pirelli Scorpion AT - similar to the Dunlops
Yokohama Geolandar A/T-S - the best of these three - good on the highway, more capable offroad.
In 2017 we made a "big trip" through Africa and had BF Goodrich T/As on the vehicle we had there - they were a little noisier on the highway, however better than all of the previous tyres offroad.
In 2019 we made a "big trip" around Australia and at that point had the Yokohama Geolandar A/T-S kn the vehicle. When we needed to replace one we found that the nearest shop had BF Goodrich T/As and we asked them to put one on the vehicle, however they recommended a Toyo Open Country AT as being as good as the BFG at a lower price. We took their advice and when we subsequently replaced two more tyres put on two more Toyos, which we have on the vehicle now (in South America). The Toyos are excellent - quiet and capable on the highway, and good offroad. So, I'd recommend Toyos. I've seen a lot of recommendations recently for Falken Wildpeaks, however have no experience to offer.
It makes sense to check sizes too, as you are. We stick to standard tyres plus one size up (so to speak). This gives us 265/65-17 tyres and we've had no problems sourcing tyres. I don't think you'd have any problems with the sizes you mention however I'd do some checking online. I just checked here in Colombia and one of the big tyre shops has BF Goodrich 265/70-17 and 285/70-17 tyres available right now. Note that it'll be different from country to country - in Bolivia we had to have some tyres sent from La Paz to Sucre to get what we needed; in Brazil they protect the local tyre industry which makes street tyres and mud tyres; we needed ATs and it took around 80 emails to find them in a 1000 Km range - fortunately we were were heading that way; the tyres were also VERY expensive because ATs are imported and have high import duty (because of the protectionist setting).
I suggest carrying a repair kit and compressor - we've had 5 punctures in our time in South America (two were sharp rocks on an unsrifaced road in Bolivia, the others were sharp metal debris on the highways); we've had zero punctures in Africa in 45,000 Km, one puncture on a rough road in Australia in 45,000 Km, and no punctures in the last 30 years or so in Europe, Asia, and North America.
