Deck Paint Over Old...Prep? Products?

[ElBichoMalo]

I know there are several good products for painting the deck, console, gunwhales, etc. I was thinking of either an Awlgrip or Interlux product. I was thinking a two-part epoxy was the way to go, rolled and tipped. Lot's of old posts to read, and I will, but here is my question:

My 73 has been painted by God knows who with God knows what. It is white, and it is chalky. What will I need to do to paint over this? Do I have to remove ALL of the old finish/finishes? Should I use the 2 part paint, or something else?