Wich player to use for backtrax?

Im looking for a good player for my backtracks that i use live. Need to have single play and good interface so i can change song fast. Ive looked at donut but it couldnt handle single play. Backtrax only use Itunes mp3 and i would like to have my backtracks backed up in Dropbox. Please tell me your setup or what you think is best. Best regards Toffe Sweden