Thanks all - I think I have all of the information required to sort out what has been one of more awkward layout issues on this car. I will be running it through the firewall opening around and up the rhs center sill . The removal of the lines from crossing over above the drivers feet provides around 30mm extra clearance in front of the upper pedal area under the dash - It sounds minor but I expect it to be a noticeable improvement . Never an issue on LHD layouts but a significant one here.
Finally, one last question, with 134a swap do you need to replace the TX valve?