where woudl I find the non-gui version
There is no separate non-gui version, if you start chdkptp with -c (or any command line option other than -g) it starts in command line mode. I suggest you read
http://trac.assembla.com/chdkptp/browser/trunk/USAGE.TXTHowever, as I said multiple cameras are currently only supported in the API. That means you'll need some Lua code to control them. There is a module called multicam included with chdkptp, which provides some functions for this, but it's quite experimental and unfinished.
I could use that for the dual cam live view
I don't understand how you expect to do live view without a GUI ? You can retrieve the data using the lua API, but you'd need to write code to display it. You could use the cameras hardware video out and video grabber I guess...
As an alternative, if you don't need the shots to happen at exactly the same time, you could run two instances of the gui. To do this you'll need connect in way that specifies each camera without having to establish a connection. This can be problematic if they are the same model. See the "connect" command in the above linked USAGE.TXT. The best way to do this is probably to open one instance, use the list command to get the dev/bus IDs and then connect using those. Connecting by name or serial number will not work, because you must establish a connection to get those, and that will disrupt the other instance.