DLCs, add-ons, downloadables, pre-o for PS3

Is there a way to post all the things which are the dlcs for newer systems' games like PS3 and xbox and etc? Japan region and versions include? Or are they somewhere on the site?
Checked the games in interest, nothing founded.
For example DBZ: Battle of Z have some pre-order content up to three characters! Is it possible to add those for the game, specifically the japanese version too? I mean it's possible to find it for Europe some places but Japan is not seem to be found.
And that's not the only example.