Intrusion detection audit

We have a client who requiresa full system intrusion detection audit. They have cisco network products including cisco firewalls as well as sonicwall and various other products. This task is to try to infiltrate their systems WITH THEIR PERMISSION and produce an audit report of security vulnerabilities and areas of security which need to be addressed. A full specification of the task / project will be given only to the chosen providor. But please ask any questions on the PMB. The budget is there only as a guide, if you feel it will cost more please put his information in the text of your bid. Thank you.