Sorry I'm asking for two separate things

1. I am unable to see Aerolinas Argentina award seats use Delta miles on the Delta website and so wanted to see if there was a special way to book Aerolinas Argentina flights use Delta miles

2. I have bought a cash flight directly on the Aerolinas Argentina site. But the flight I really want is ~5 hours earlier... and also several hundred USD more expensive. I am trying to get a sense of how realistic it is to try and do a same-day standby on the earlier flight... or will I end up paying the same or more that way?

thanks