And here's one out of left field...
Has your boyfriend ever tried a Doo Rag? OK, so it's not a "hat", but it does cover his head... so it's not completely off topic. I know zippo about what kind of hat fits what kind of face. All I know is my brother-in-law is similar to your boyfriend in being tall, slender, and having a somewhat narrow head/face (AND lives in Rhode Island!). He's usually a very conservative fellow (he's a professor who is mad with science). There's one game a year (I forget football or soccer.... whatever) that he and his students wear doo rags to. I don't know why, but he looks great in one.
Has your boyfriend ever tried a Doo Rag? OK, so it's not a "hat", but it does cover his head... so it's not completely off topic. I know zippo about what kind of hat fits what kind of face. All I know is my brother-in-law is similar to your boyfriend in being tall, slender, and having a somewhat narrow head/face (AND lives in Rhode Island!). He's usually a very conservative fellow (he's a professor who is mad with science). There's one game a year (I forget football or soccer.... whatever) that he and his students wear doo rags to. I don't know why, but he looks great in one.