Ended up with braided under the dash to the pots on the firewall. Steel lines for the front in the engine bay, with braided flexi lines to the calipers.
For the rears, I have run a steel line inside the cab, down along the floor, then exit near the diff hump, with braided flex to the diff. At the moment the rear caliper lines are still the original rubbers that came with the calipers.
I could see the point in exiting the rear line out through the fire wall, only to then run it back all the eay under the car. Running it along the insight protected it from exhaust heat and possible damage.
In hindsight, rubber flexi lines to the pots under the dash (low pressure) would have been easier to route and more than up to the job. It gets fairly tight for room under there and the braided lines are harder to position given their limited flex.
Have a look at Phils cortina project, He has braided lines through out his engine bay.
Shaun.