If it were me, I would buy two products:
First I would buy something like AIO or Meguiar's ColorX which have pretty strong cleaning abilities. I would also buy a product that has some very light cleaning ability like NXT, Mothers' Synwax, or PB's EX. Then, I would use the AIO or ColorX to get the stronger cleaning and light protection. At my first chance, I would apply some Synwax, NXT, or EX which would provide some additional light cleaning but stronger protection. Then, I would alternate coats when I had the time.
If I could pick only one, I would go with PWC or Medallion PPP. However, Meguiar's discontinued MPPP, so that narrows it down pretty quickly.