MP3/WMA/WAV/OGG/FLAC Shield for Arduino Leonardo: is it possible?

Hi to all, this is my first post here.. I recently purchased my first Arduino board (Leonardo model) and I like to make it play MP3 and generic audio files (such as FLAC/WAV/WMA/OGG).. What do I need to play these files from an SD Card and listen them with (which?) loudspearkers?

Thanks

Need an card like one of these
http://www.mdfly.com/index.php?main_page=advanced_search_result&search_in_description=1&zenid=7bb148a0794958999d74eee7c07b7138&keyword=mp3&x=-310&y=-103

May not do all the file types.
Connect the output to powered computer speakers, will sound great.

Other choices:

http://www.ruggedcircuits.com/html/rugged_audio_shield.html