Hello Tiergan,
Just in case you are unfamiliar, the Player Character pages in the RPC Wiki will occasionally have a "Rumor" section, usually close to the bottom, with various teirs of difficulty in hearing the rumor. Since these are already assigned by the given Roleplayer perhaps you could use them to fluff out your database of knowledge on a given character. (Of course they stand to be in the more common way than information a professional broker might have, but I thought it a possible start.)
Cheers!
Just in case you are unfamiliar, the Player Character pages in the RPC Wiki will occasionally have a "Rumor" section, usually close to the bottom, with various teirs of difficulty in hearing the rumor. Since these are already assigned by the given Roleplayer perhaps you could use them to fluff out your database of knowledge on a given character. (Of course they stand to be in the more common way than information a professional broker might have, but I thought it a possible start.)
Cheers!