You may want to get some more expert advice on this, but here are my thoughts.
The firewall vacuum booster, dual circuit master, and separate clutch master I think would be your best choice.
For the clutch master I would look for an master cylinder originally designed for a clutch, a mid to late 60's Dodge pickup could be ideal.
Hydroboosted drum brakes are not recommended, although it has and can be done, they tend to act funny.
I see no problem with your original brakes and wheel cylinders if you add a vacuum booster, it will help some, but not as much as boosted disc brakes.
Grigg
