Disconnect the power to the tcc
Any cable shifter could be made to work. I am a bit puzzled about the "manualised" thing though. If you only manually selected gears via the shifter, AFAIK you'd loose 4th and any access to converter lock.
I don't like the commercially available pushbutton shifters either (I'd quite like a winters shifter) but I'm planning to wire the tcc power though the 4wd light so the trans runs "full manual" when in 4WD, but auto in 2WD. I can pushbutton control converter Lock and OD, which I don't really want in 4wd (OD that is)
Steve