Due to our Muncie 4speed business, I get a fair amount of questions about clutches and linkages.
Generally I try to nudge the customer in the direction of the OE Z-bar setup. Its usually something they're familiar with, its simple and it flat out works. It seems a lot of the Hyd conversion setups have a higher than normal failure rate (whether its bad parts or an installer who isn't well versed in the application and unintentionally messes it up).
Additionally; due to the support for the OEM 5 and 6 speeds we do, I have to keep up with the guys at LS1tech. Under their manual transmission forum is page after page of 'clutch doesn't work', 'can't bleed the clutch', 'bad pedal feel' etc.
That being said, sometimes Hyd is your only option. Learn the system from front to back and try to use as many OE components as possible to make sure it is easier to service as time goes on. For this kind of thing, Upstart Hot Rod Co. might have a neat slave cyl. but, if they go out of business, is it going to create havoc to get proper replacement parts?
To the OP: Let me know how the Muncie 4spd adapter works out for you. I've had several people ask about them, but I have no knowledge either way
On a side note: Ansen made a pedal assembly that was dual master cyl for the brake and a single for the clutch. Seemed very compact and 'period', although I don't know if they worked well or take standard sized seals and bushings. They pop up on flEaBay occasionally (although not right now