I think what Scott actually meant was Hydra-Vac, not Hydro-Boost. The Hydra-Vac is a remote mount booster run off engine vacuum. I think that Midland still makes them. They were popular in the '80s on Pro Street cars. They would use a frame munted master cylinder with that booster to clean up the firewall for appearances.
On that booster kit from Brother's that you mentioned, the type of trans shouldn't make any difference. In fact, I'd think that there would be more room with a manual trans over an automatic.
