Cisco Firewall :: 5510 / Adding AIP Firewalls To Existing CSC Firewalls Setup?

I have a customer with active/standby on a pair of 5510's with the CSC modules. They were inquiring about the AIP/ASA, and since this would NOT work in their current setup, would getting a pair of 5510/AIP configured for transparent failover work placed in front fo the existing units? Would I need to have a switch placed between the AIP and CSC ASA's?  Or would I setup the ASA's for context based Active/Active failover to interconnect the ASA's to the existing units, but I still see a need for a switch.