Denise, I think your choice of camera is superb. If I were to start over or have an unlimited budget I would go for the Sony world. All the work I have seen produced with those cameras is phenomenal and I think your choice of 28-70mm for the kind of image creation you plan to do will yield fine results. Look forward to seeing some of your work here.
While the I-Pbone X sounds like a fine "camera" I am afraid by the time it gets to Peru the price even on a carrier subsidized plan is going to be more than what I am willing to commit. I do plan however to upgrade from the 6S to 8S.
Have fun with your new camera.