I find PP a bit stronger abrasive-wise compared to #80 but I find #80 hides remaining marring better. IMO they're both easy enough to use by hand. You can pretty much take your pick. If it's a dark color, or if you're likely to have marring left over after you polish, I'd probably go with the #80. But I have, and use, both and IMO you won't go wrong either way.
I use a MF instead of terry, but ScottWax has plenty of experience to back up his choice of terry so take your pick on the choice of applicator too.
The "clear it out" means that when you've worked #80 long enough to break down the abrasives it'll turn clear (or on odd, rare occasions *pink* :nixweiss ), which is quite different looking than it's original brown-olive color. Watch for when the color disappears, that's when you quit working it. (Scott- Hope you don't mind my answering this as I was posting anyhow)