Depending on water quality copper Type L above ground K below ground if your codes permit
CAST Iron above ground for a quiet long lasting system non carcinogenic and proven longevity unlike the many,many documented "state of the art" plastic failures
Many of the homes I work in in NYC were built in 1922 or before and the brass water lines I would venture to say will last another 40 years. The Cast Iron sewers other then minor root infiltration could give another 20 -30 years of service.
Just because piping is old doesn't mean it has to be replaced.
Before you just arbitrarily re pipe hire a local licensed master plumber SELF Employed who works in the area and ask him /her who they work for in your area then ask their opinion on the pipes remaining lifespan.
Self employed LMP's do depend on word of mouth advertising
If a contractor does the job right for someone they tell 3 people If they screw one account that victim will tell everyone "don't use that crook/ incompetent etc"
Just make sure they are licensed and insured.
Look at the NYC water mains which some are still made of WOOD....
Want to talk about old look at the Churches in Europe with original copper
flashings over 1,200 years old Plastic does not have this proven track record
Look up on Google plastic piping failures and see the screen light up.
Have any more questions please feel free to ask