308GT4 Water pipes. Stainless steel suitability?

My 1974 308GT4 has the usual problems with corroded and leaking "through chassis" water pipes. Whilst a temporary cure using flexible hose is in progress, I need to replace with permanent metal pipes. Please can anyone advise if there is likely to be problems (chemical reactions) which could result if I use stainless steel material? Anti-freeze mixture is essential, and avoiding any problems especially with the aluminium engine is essential.

Also, could someone kindly give me the accurate actual length - around the outside of the 'engine end' curve of the long water pipe - or pipes if they are different lengths. Many thanks.