I installed a servo in my car during my build.
I used a new remote dual circuit servo which I fitted under the bonnet and plumbed in between the master cylinder and the front and rear brake circuits. For the front this involved blocking off one of the front circuit master cylinder outlets and then T'ing the output of the front servo circuit to the left and right front discs instead.
To route the vacuum I ran 5/16" kunifer hard line on the chassis from frame horns to frame head along the side of the centre tunnel. I then used booster hose for the last foot or so at each end.
My first engine (1641T1) ran kadrons so I could source the vacuum from the manifold balance pipe. For my current engine (2270T4) I tapped one cylinder on each manifold, and Tee'd them together. I fitted a valve in each feed line (from a T2) hold the vacuum for the booster (and to keep the two cylinders from interacting).
There are various build pictures in the "original build" section of my website. www.chesiloutlaw.com