As for the computer....

Are you going to take a backup or organise one for while you are there? How about getting another harddrive with the same stuff on it in case that goes down.

Have you got driver disks and program install disks made up? Have you made a backup of your live session including samples etc?

have you checked plugs for loose wires and are you taking spare fuses for all your equipment?

Have you got some tracks on Cd or vinyl you can play as a stop gap if it all goes tits up or you need a bit of breathing space to sort out an issue?

just a few ideas, im sure it will go well! im looking forward to hearing the recording!