using the mpc live?

Hiya,

I'm a real mpc-newbie and currently own a SU700.
But since the SU is a bit limited for my live-perfomance-needs.

This is what I need:

-I want to perform live with an mpc and some external hardware.
(samplers, synth, anything). It's not for my studio at home.

-at the moment, my tracks are on my pc. I use a lot of
softsynths. How can I convert the
song to an mpc? It reads midi files, right?
(my plan is to export each track to .wav and load it into the mpc).
I don't want to re-sequence my songs all over again.

-also, is it possible to load multiple tracks ? It would be very cool
not to stop the playback. I'm really looking for a live-perfomance
without breaks. Can you load songs during playback without
problems?

-which model can be recommended? 2000? 2000xl? 1000?

thanks guys!

-Mochi