I'm sure you can connect the speakers to your 3000, but unfortunately, I'm not familiar with that particular system.
As for finding midi files, the best search engine for midi files is www.musicrobot.com
which will usually list huge numbers of song files of various lengths. If you're looking for midi files with imbedded lyrics, check out www.vanbasco.com
PSR-S950, TC Helicon Harmony-M, Digitech VR, Samson Q7, Sennheiser E855, Custom Console, and lots of other silly stuff!