I usually create all my backing arrangements on a Korg i30
arranger and fly the MIDI sequences to Logic Audio running
on a Dell Laptop for further editing/revoicing.

Logic plays back the polished MIDI sequences through
a series of external sound moudules and synths and
all the volumes and pan settings are automated and
fine tuned with Logic Control.

A Mackie LM3204 mixer acts as an audio patch bay and
feeds directly into an Alesis ML-9600 Masterlink hard
disk recorder for final mastering.

I have a few pictures of my setup here:
http://silverhawk33.tripod.com/glenskorgsite/id25.html

Regards,

Tapas