"medium-size dark fedora ... extra large black Stetson"
Although Mr. Halloway speaks of black hats and white hats to contrast Jim and Will, respectively, the only specific hat styles he cites are both for Jim. A fedora is a felt that is creased lengthwise along the top and pinched in the front on both sides -- the classic gangster’s hat. Stetson is a particular brand started by the John B. Stetson Company of St. Joseph, Missouri in 1865, which made (and still makes) a variety of hat styles but is probably best known for cowboy hats. A black Stetson suggests a lawbreaking gunslinger.