A lot depends on exactly what you want to do. I would probably place the ASAs as a failover pair at the outskirts of the LAN switch
assuming that your internal network lies behind that. I would place the IPS behind that. The ASA with proper access-lists will clean up the traffic quite a lot and minimise traffic inspection load on the IPS. You really want the IPS only to inspect relevant traffic (not ipsec, https etc). The ASAs can also be used to terminate VPN using the anyconnect client. Not sure what the ADEs do.
Matthew
