I am looking to travel during the second week of March (exactly one year from now) from Cedar Rapids, IA to Quito, Ecuador.

I need some advice.

I have ~58,000 United Miles
I have ~71,000 US DMs

I also have 80,000 Priority Club Points that should be making their way to my account from Chase soon.

During March, supposedly, its only 35,000 miles RT on US to fly from US to S. America, but United has a lot of availability online and is part of Star Alliance.

Here are my thoughts, please give me some advice:
-Converting my 80k PC points to 40k DM by April 15th via the hotel points conversion deal. (my conversion rate is based off of a post on Mommy Points)
-Buy some miles with the 100% bonus rate
-Try to buy one ticket (buying 2 RT tickets) via US and one via United, aiming to have both on an United flight.

This will only be my 4th award flight booking so any advice would be greatly appreciated!!