Some people like the 767s in C, but I find them really cramped. The C seat in an AA 767 is actually the same width as a Y seat on 777 (18.5"). That being said, leg room is very good and recline is fairly good, just make sure you aren't in a bulkhead seat as these have significantly less legroom.

Whether to spend the extra miles on an F ticket is a matter of opinion and how much room you need to sleep.