80/20s are brighter; PBs are warmer. This is the general difference in timbre between these two string compositions. That said, Elixir nanowebs tend to sound brighter than others I've used like D'Addario, Martin, and Dean Markley ...in my experience anyway. So like all things "tone," you have to hear and judge with your own ears what works better on your particular guitar, Taylor or otherwise. Everyone has their own definition of "good tone": one man's "bright" is another man's "clear," or yet another's "brash" ...same goes with "warm" for one is "dark" or even "muddy" to another. Then there's the whole love/hate thing with coated strings, so this is something you should decide first.
But as for your specific guit, may I suggest (since you asked
), elixir PB nanowebs in a medium-light gauge which will give you a bit more bass oomph on a GA body, but still offers the lighter feel for the GBE strings. I love these, and I've found them to work on every GA and GC Taylor I've owned in the past, and currently a GC-body I own now. No substitute for experimentation, of course. But to help keep the cost down (esp since elixirs are pricey), think about which tonal direction you lean toward, and then go from there.
Edward