Cisco :: Setup A Juniper VPN Into ASA 5520

I have a ASA 5520 with a functional IPSEC VPN using the Cisco VPN client. This allows my remote users (Staff) using laptops to come in from anywhere on the Internet and tunnel in. Works great.Next, we need to stand up a VPN over a Juniper SSG5 so that when we have groups working outside of our network, they can tunnel back into our network. If they were going to be coming from a known, fixed IP, or even netblock, we'd probably use Route-based setup from a Juniper SSG5 into the ASA 5520. But they may very well be coming from any IP. I am thinking this leads us to Site-to-Site VPNs- it won't be Network Client access obviously, nor will it be Clientless (browser-based).