You can control the zones by driving the IR output of your control method to the IR input of a keypad assigned to a zone. Using the IR commands from the ZR-8630, the niles R-8 commands are probably already in you library.
And the RS-232 control limitation, of using a 232G for each zone to be controled, yea, It sucks, but, it is what it is!! But I think they now have published the zone selection commands, I think, so that is no longer an issue!!
I Have not even needed to lately
I sell a shitload of ICS with the ICS interfaces, and sources and move onto the next job!! Plug and play!!!
And as soon as those guy start shipping the iRemote TS, that is the bridge everyone is looking for..
Damn it Niles, When,When,When???