You might also want to look at the PSR-550. The DGX's that George mentioned are good, but they are limited in recording features. The 550 will give you 16 tracks, plus a style recorder that does loop recording.

The Casio WK-3500 is also a good choice. It doesn't have the recording power of the PSR-550, but where it lacks in recording it surely makes up for it in other features I used to own a PSR-550. Not a bad board. Sounds are decent, and features are pretty good. My problem was that the sounds weren't how to say "hard enough" for me, and the style I play.

Squeak

Squeak