Im not sure what you mean by the statement that Elan does not interface well with HAI - because there is a 2 way driver that Elan has written for the Omni and thus it can be controlled via Elan touchpanels.
HAI has updated its touchpanel firmware and the firmware on its panels to support Russound's multi-zone unit. This just means that you can use HAI touch panels to control your zones - but that also means you are spending $700+ for a touchpanel that - at the end of the day - is useless as it cannot actually be programmed worth a squat (yes, i know it can display shortcuts to things you create with its programming software - but the UI cannot be modified).
I dont think Russound's multi-zone audio controller is in the same league as the Elans - The S12 allows you to distribute both composite and HD video via component and of course you can distribute to more zones. If your need is only to distribute audio, then the S12 is overkill and there are better multi-zone products IMO.
There are some other multi-zone controllers that also distribute HD and audio (one CI on these forums recommended the ADA System 16). If you are going to spend S12 type money, you might want to consider that as well.
One suggestion - if you are going to install touchpanels immediately, you might want to stay away from Elan. You ought to look at AMX, Crestron, or Dean's product. If you can wait a few months, my sense is that Elan will finally update its software to support their new house controller device (which is designed to do some of the things AMX & Crestron can do). There are other options of course beyone the 3 I mentioned - Homelogic supports the S12 as well.
FWIW - I have had my S12 for 8 months - and its been rock solid.