Larry:
No matter which throwout bearing you select it still must run concentric on the snout of the gearbox.
What you are referring to is an external slave cylinder, with a thru shaft and fork to engage the throwout bearing.
I personally think it is a great setup, as throwout bearings for the most part are very reliable if installed correctly and should not need fussing with once you sort out the whole deal.
Also, changing slave cylinders does not require splitting the motor and gearbox, and no leaks around the clutch from a bad internal slave.
If you can keep posting as you do your setup, I am sure others would be interested in the configuration including myself.
Cheers
Phil