I'm starting to think this may not be possible. I didnt include some info in the original post, because about a week ago a new issue occurred that I didnt have originally. Even despite all this, one day about a week ago I rebooted and it just froze up on the AT&T logo. Factory reset and data/dalvik wipe didnt help, issue persists. So that's what I meant when I said that the phone is non-functional.
I dont have a laptop right now but a friend says he will let me borrow his to do this. I dont know if I'll be able to install the Z992's drivers (they seem to only be on the phone, cant find a download for them). Will I need the Android SDK as well? If so then which parts (no sense in DLing the whole thing just to get to one component)? Presumably I'll just need ADB and fastboot. I can still get into recovery as well.
I'm not going to attempt anything just yet, considering that the PC may not be able to make contact with the phone via either ADB or FastBoot. I'll need some clarification on this first.
Once all this is done I can UL it to my Dropbox and post a link.
As far as a custom ROM is concerned, I think what would be optimal (for myself and others) would basically just be a modified stock ROM with all the non-essential apps stripped out (by non-essential I mean any app that isnt absolutely essential to the phone's operation). With a option in the installer to select which ones the user might want. And maybe an option to install the latest (Gapps/Google Apps) package. But maybe you can think of something better.
Thanks again!