I didn't want to hijack the Xenon thread any more than it has been, but I shot an email to Jason at All Hyundai and Isuzu to check on a used master brake cylinder for you (they have one Vehicross left in stock)... here's the response:

The brake master cyl sells for $65.
Please call for more information.
Thanks,
Jason
888-944-7898
916-635-8951

Give him a call if you are interested and let him know Adam gave you this info so he doesn't say someone's already looking into this part.

Good luck!