I went to Lowes this morning, and they have 8" x 8" glass blocks in two different thicknesses: 3" and 4". We'll get the 3" ones because then we can have a small ledge on the inside.

This morning I also received an email from James Lo (Sunnyvale Lumber) with an updated quote. This one is for a Jeld-Wen A110 3' 6" x 6' 8" fiberglass door with a 3-light transom above it.