Hey mate,
Just played this game myself recently. From the research I did, there seemed to be 3 main options.
Dual master cylinder bolted to the firewall. I tried this option, bought a master cylinder (will have to check sizes) to suit a Datsun 1600 and had conversion plates made up to suit. If you are interested in this, I have unused parts that I can help you with.
Pedal box assembly. This is what I did with a Paul Dunstan modified standard escort pedal box. Dual masters with a balance bar. Fits, works well, very happy with pedal feel, drive ability etc. Also have the option to go hydraulic on my clutch which is a good option for the future
Final option would be incorporating a remote brake booster. Also bought one of these but only as I was told I couldn't get the car engineered without it. This proved incorrect so that is also sitting unused in storage.
Sizing of the masters depends on front/rear caliper size. Paul Dunstan also has a conversion kit to install Nissan r31 Skyline rear calipers and ditch the OEM drum brakes. Great idea and worth doing if you are doing the rest.
Definitely worth getting an engineer on side before you start but seems to be a few guys in Vic. I am in QLD so can't help with names.