E-glass or normal fiberglass cloth - 6 oz. or less on the deck top. You're trying for transpariency so regular glass wets out easiest and best with plenty of strength. All the suppliers who sell epoxy also carry glass cloth and have the type you need for your project.

S-glass (structural glass) is heaver and used where extradoanary strength is needed and does not wet out easily. (heavy and large boatbuilding)

Satin is shiny and smooth and sometimes the weave is tight. I personally don't like it and find it doesn't wet out as nicely as regular glass and sometimes traps air. It also creates a lot of fuzzy strings after cutting which is a neusance.