Any other alarms use Cliffnet?

yes, it is... you're correct.

However, cliffnet software will work with any Clifford alarm that uses the cliffnet data port.  I have an Avantguard 5 and when I load up the software it asks me to select from an entire list of Clifford alarm systems, which one I have.  Though I have not owned any other Clifford system OTHER than the AvantGuard 5, I'm assuming that most other Clifford systems use, or are compatible with, the cliffnet wizard software.

Also, Clifford is scheduled to release a NEWER version of the Avantguard 5 this summer that includes two way remotes.  If you CAN wait until then (I couldn't), then I'd wait for that alarm.

Oh, you'll also need to find a DEI reseller that is willing to sell you one "over the counter", contrary to DEI reseller policy.  Good luck on that, but it is possible.

Hope that helps!   

Oh... By the way...

http://directechs.com/techsoft/cliffnet/WizPro220.EXE