OP, since you're going to shoot environmental portraits you'll be working somewhat closeup. Lenses' circles covered with good enough image quality at the edge are measured at infinity. Lenses that won't quite cover 8x10 at infinity will probably work for you.

Since you're going to be shooting environmental portraits, is what's going to be in the corners of the frame that important?

If you need it all, the lens for you is a Schneider 210/5.6 Super Symmar Aspheric HL, which Schneider claims covers 357 mm wide open. Dig deep ...