John,
For the ASA5505, yes you need a Plus license to access traffic between LAN/DMZ and vice versa.
But with ASA5510-BUN-K9 license on the 5510, you should be able to use upto 5 interfaces.
ASA5510-BUN-K9
Cisco ASA 5510 Firewall Edition Bundle
Includes: 5 Fast Ethernet interfaces, 250 IPsec VPN peers, 2 SSL VPN peers, 3DES/AES license
⢠300 Mbps Firewall
⢠170 Mbps IPsec VPN
http://www.cisco.com/en/US/prod/collateral/vpndevc/ps6032/ps6094/ps6120/prod_brochure0900aecd8048dba8.html
Regards,
Arul
*Pls rate if it helps*