As an enthusiastic Tyros2 keyboard owner, and also one who's auditioned and played all the kbs you've mentioned, and realizing (from what you say) that you're just "pretending to play keyboard", I urge you to STOP PRETENDING, step from behind the keyboard, and focus on giving your best (to the audience) as a singer, and go with an arranger module like the Ketron Midjay instead. Though I personally recommend the Tyros2 for 'auto accomp mode' style keyboard playing, for strictly SMF & kar file playback, the Ketron Midjay is the clear winner imo, as its sound palette is ideally matched for SMF/Kar files, and includes better SMF/Kar file navigation features as well. Afterall, Ketron named the Midjay for a good reason, as evidenced by the words Mid(i) and DJ included in the title.

Scott