In the Aconcagua area there are still other peaks in the area that can be done in a shorter amount of time.
For example, Marmolejo is over 6000 meters and would be more doable on a two week trip. Still, flying that far for a two week trip isn't as "efficient" as if you had more time.
Ecuador is nice, as mentioned, but also as mentioned some of the peaks don't have an expedition feel.
Antisana was my favorite climb in Ecuador and doesn't get climbed near as often as the mountains with the huts.
Some mountains in Ecuador definitely are at least a mini-expedition. El Altar is a good example.
Of course those peaks do require some technical ability.