I would imagine that you are going to be limited to surface mount, or chip LED's since getting that large of a viewing angle is hard. Surface mount devices tend to have wide viewing angles because of the small distance from the die to the lens. You will also have to decide how much intensity you can sacrifice given the angularity you require. Off-axis intensity drops quickly in regular LED's, one look at the photometric charts will show that you are asking alot.
here are two makers that have pretty easily searchable lines: