A stronger engine doesn't have to work as hard to pull the same weight, so it will last longer. Especially true if you have hills.

It will burn more fuel though, so you have to decide if it's worth the added cost.

The 4 banger... better fuel mileage and fairly simple to work on. 6 shooter... more power really. Both are rather reliable motors but that 4 banger Toyota has is almost indestructible it’s not uncommon to see those things go over 300k miles.   

4 cylinder is quick enough but the V6 does get good gas mileage compared to other V6 SUVs but the again if you don't need it 4 cylinder is best. 2012 was the last year of the generation and they solved all the engine problems by 2009 or so and the earlier ones had transmission problems so you are avoiding all of that. Make sure to have a mechanic check out whichever one you are considering. 60k is nothing for those.  Price is also important. I saw a 2012 V6 with 50-60k miles going for $17,500 which is absurd.

Get the 4 cylinder. Less maintenance costs and better mpg.