Hi Squire
Seems like we haven't heard from you in a while, good to see you're still around. The simplest answer to your first question is:
Nylon ribbons are the cheapest and most resiliant, but don't hold as much ink as silk or cotton. Cotton ribbons hold the most ink as the ink actually soaks into the fibers of the ribbon. However, cotton ribbon will eventually break down with the repeated hammering of the type slugs and will plug up the letters with cotton pulp. Silk ribbons hold more ink than nylon but not as much as cotton. Silk is also a finer weave so gives a clearer impression than cotton or nylon. However, silk is the most expensive and usually only comes in black or black/red.
As you are in the USA, my recommendation is give Lanie Hurwitz a call (800) 250–7426 or visit his website. Lanie has all sorts of colors and loads his spools full. Hope this gives you something to work with,
Sky
We humans go through many computers in our lives, but in their lives, typewriters go through many of us.
In that way, they’re like violins, like ancestral swords. So I use mine with honor and treat them with respect.
I try to leave them in better condition than I met them. I am not their first user, nor will I be their last.
Frederic S. Durbin. (Typewriter mania and the modern writer)