Since the surface is sloped, having something that could withstand a hail storm seems prudent. What about a polycarbonate panel like this
? You could butt them up to each other so the open end cells overlap, a little silicone to bind and seal them, and they should be light enough to only need support at the top and bottom and the ends so no shading. Otherwise if glass is the only option, perhaps some shower doors would work? A T channel between them like this
could support the glass, and a gasket on each side of the glass could thicken it up to seal it. A channel for both inside and outside that overlap/touch, then the glass and gasket would fit into the gaps if that makes sense? Shower door glass shouldn't have any UV coating.
Edit: the first link also has this channel
for connecting them together for a 1 stop shop option.