Based on the many recommendations I made these two purchases:

Coolibar Rhodes Shirt: https://www.coolibar.com/colle.....riant=4794

Uniqlo Airism Hoodie: https://www.uniqlo.com/us/en/p.....ayCode=003

The Coolibar shirt is everything I was looking for. I bought it in White so I could put it on over anything else I was wearing. It is so light and soft and looks like a classic white shirt in style. It's a little sheer to really wear alone (for me). I thought I was sizing up and bought L, but it's just loose, not the real "big shirt" vibe I was thinking. Plenty loose to go on over other tops though.

The Uniqlo is light, but not as light as the Coolibar. I'm keeping it anyway because I've been missing a light jacket and this can fill that need and the sun protection also. I bought L on this one too and I could have done fine with a M. That's just to say, I thought Uniqlo would run small and this at least didn't.

Thanks for the help earlier!