This not really helps, since it is way to complicated to search trough all the airline websites and to figure into wich booking classes certain tickets book. Specialy since you are not going to book a "booking class" you are going to book a certain ticket - and this randomly maps into certain booking classes, which you only see after you bought the ticket.

The typical search engine let me search for Enconmy class or Business class but did not let me search for lets say "J" or "P"